page 4

Remarks

Thomson's material was dredged in Lyttelton Harbour (depth unstated); that described by Stock (1954) (a single ovigerous male) was collected at Dana Station 3632, Auckland, New Zealand, in 5–30 metres. The present material extends the range of this species down to about 380 fathoms, and, if material in the writer's collection from the littoral zone of Lyttelton and Otago Harbours be also considered, the animal's range may be considered to extend from low water spring tide mark to 380 fathoms, and geographically from Auckland to Dunedin. The material in collections 48, 49 and 55 was all taken within a period of two days; none of the males was ovigerous, but numerous large ova could be seen in the femoral ovaries of the females.

Stock (1954) notes that in his specimen "the chelifore scape has not such a prominent dorsal tubercle in its middle as figured by Thomson". It should be pointed out that there is some variation in this character, but a tubercle or clump of spines is present in this position in all the material examined. Similarly the tubercles on which the genital apertures are situated are much higher in the males than the females. As is usual in the genus the ovigers are more strongly developed in the males.

Description

Trunk slender, smooth, without spines, clearly segmented, lateral processes separated by their own width distally, less proximally; length of cephalon equal to length of last three segments; cephalon with a slight constriction between the bases of the palps and the first lateral processes, and produced anteriorly over the base of the proboscis. Ocular tubercle conical, rounded at tip, height greater than diameter at base; four eyes.

Proboscis long, cylindrical, with a slight median swelling, ventral surface of tip of proboscis covered with fine spines in female, fewer spines in male.

Abdomen fusiform with a slight median constriction, rises from trunk at an angle of 35–40°; reaches beyond the end of the first coxa of the last leg.

Chelifore scape of male distinctly 2-jointed, suture between joints oblique, joints swollen at suture; female scape apparently composed of one segment, with three fine hairs where one would expect to find the suture. Fingers of chelae at right angles to the proboscis; immovable finger slightly longer than dactylus, tips cross when chela is closed. A number of fine irregular denticulations are found on the middle of the cutting edge of the dactylus. Fingers of the chela shorter than the palm. Fingers of male chela not as well developed as in female. A prominent spiny cushion is found at the base of the dactylus in the female but not in the male.

Palp a single, short, bluntly pyramid-like joint, slightly longer in male than in female.

Oviger 10-jointed in both sexes, as is usual in the genus this limb is better developed in the male than in the female. Fourth joint the longest, and in the male this bears a slight lateral swelling, joints 7–9 with lateral setae on their inner margins. The terminal joint of the male bears five spines. The length of joints in mm. in male and female are given below:

Joint	1.	2.	3.	4.	5.	6.	7.	8.	9.	10.
Male	0.7	1.95	1.2	2.2	1.95	1.1	0.8	0.6	0.4	0.3
Female	0.6	0.85	0.5	1.1	1.1	0.55	0.4	0.4	0.4	0.25

Third Leg long, slender, sparsely clothed with fine hairs; the first coxa is half as long as the third, which is half as long as the second. Femur and first tibia of equal length; femoral cement glands of male with ducts a little shorter than width of femur, inserted at 5/9ths of femoral length; second tibia is the longest joint, and relatively longer in female than in male. Tarsus very short with a group of stout spines on the ventro distal extremity, propodus small, all basal spines stronger in the male than in the female, where there are four well developed basal spines and a number of smaller spines inserted distally to these; terminal claw half as long as propodus; auxilliary claws well developed.

page 5

Genital apertures are placed on small swellings on the ventral sides of the distal portions of all second coxae in the female, but only on the third and fourth in the male.

Measurements (in mm, holotype first followed by female paratype in brackets).

Length proboscis 4.0 (5.6), width proboscis 1.1 (1.5), length cephalon 3.6 (3.5), width cephalon 3.9 (4.6), length abdomen 2.2 (2.7), total length 11.2 (11.7), width second lateral processes 4.4 (4.1), length chelifore scape 4.4 (4.5).

Third leg of holotype, and fourth leg of paratype (both third legs of paratype damaged): first coxa 1.1 (1.2), second coxa 4.1 (4.9), third coxa 1.95 (2.2), femur 10.0 (15.7), first tibia 11.5 (15.7), second tibia 15.6 (21.3), tarsus 0.55 (0.55), propodus 2.2 (2.2), claw 1.1 (1.1).

page 6

Remarks

I have some slight doubt as to whether the female specimen is in fact of the same species as the male described here or of another very similar and undescribed species. This matter cannot be taken any further on the material at present available. The lateral swelling on the fourth oviger segment of the male is reminiscent of the subgenus Pallenopsodon Stock (1956), but since this species has a tubular duct to the cement gland, and differs in the armature of the 10th oviger joint it is no doubt to be placed in Pallenopsis s. str. I name this fine species after the mythical Maori figure Maui, who is said to have fished up the North Island of New Zealand, and was therefore probably the first man to have fished in Cook Strait.

Description

Trunk distinctly segmented, without spines or setae, rather slender, lateral processes separated by about half their own diameter; cephalic segment almost equal in length to the other three segments, produced a considerable distance over the base of the proboscis. Height of ocular tubercle equal to the diameter of the tubercle at the base, rounded above, four eyes with a pair of rounded eminences on the dorsal surface. (Fig. 20.)

Proboscis cylindrical, uniform diameter throughout its length.

Abdomen long, fusiform, reaching to the middle of the second coxa of the fourth leg; rises at an angle of 30° from the trunk.

Chelifore short, stout, scape distinctly two segmented, the first slightly shorter than the second, chela at right angles to scape, fingers longer than palm, when closed the slender tips of the fingers cross.

Palp a small papilla between the bases of the chelifore and oviger.

Oviger very small, of five segments, obviously immature.

Third leg long, slender, coxae subequal, femur and first tibia equal and longer than second tibia, tarsus very short, propodus rather bulbous with a lateral row of small spines, no basal spines, terminal claw half as long as propodus. Auxiliary claws absent.

Measurements (in mm). Length proboscis 1.25, width proboscis 0.5, length cephalon 1.2, width cephalon 0.9, total length 2.4, width second lateral process 1.25, length abdomen 0.65.

Third leg: First coxa 0.5, second coxa 0.6, third coxa 0.7, femur 2.0, first tibia 2.0, second tibia 1.5, tarsus and propodus 1.0, claw 0.5.

page 7

Remarks

The specimen is immature, the ovigers consist of only five segments, and the genital apertures appear to be absent. The interest of the specimen lies in the fact that it was taken in a plankton tow net at 600 fathoms. As the net used was of the open type this specimen could have been taken at a lesser depth, but as the water in the vicinity of this station is about 800 fathoms deep there is little likelihood of its being picked up off the bottom. Gordon (1932b) reported an immature specimen of "? Pallenopsis" (= Pallenopsis calcanea Stephensen 1933?) taken in similar circumstances from 850–1100 m in the South Atlantic off the coast of southern Brazil. Similarly, Carpenter (1905) reported an adult of Pallenopsis holti Carpenter = P. tritonis Hoek, taken with a tow net in 382 fathoms off Achill Head, Ireland. Stephensen (1933) and Hedgepeth (1948) both record P. calcanea from tow nettings; the latter author remarks that it is "evidently a bathypelagic species". The present specimen resembles Gordon's and Stephensen's figures of P. calcanea in the presence of a pair of small tubercles on the dorsal surface of the ocular tubercle, but differs from that species in the chelae, legs, and ovigers. This specimen does not appear to be the juvenile of either of the species of this genus so far recorded from New Zealand.