Synoptic Keys to the Genera of Ophiuroidea
Subfamily Ophiolepidinae Matsumoto, 1915
Subfamily Ophiolepidinae Matsumoto, 1915
1 (28) |
Tentacle-pores well developed throughout arm. |
2 (5) |
No tentacle-scale. |
3 (4) |
Disc thin and flat covered by scales and large radial shields, and bordered by a row of marginal plates which are erect and movable, being attached only by their proximal margins. . . . Ophiophyllum Lyman, 1878. *petilum Lyman, 1878. Kermadec Is., N.Z. 600 fms. |
4 (3) |
Disc and sides of arms covered by fine scales, which are swollen and resemble coarse granules: radial shields inconspicuous or hidden: upper arm-plates separated more or less widely by intervening small platelets: lowermost arm-spine sometimes serving as a tentacle-scale. . . . Ophiopenia H. L. Clark, 1911. *disacantha H. L. C., 1911. Bering Sea. 50 fms. |
5 (2) |
Tentacle-scales present. |
6 (27) |
Tentacle-scales well-developed throughout the arm. |
7 (20) |
Dorsal arm-plates entire, not fragmented nor divided into supplementary plates. |
8 (9) |
A row of papillae skirting the outer borders of the gential scales and radial shields: a pair of plates wedged between the radial shields: arm-spines minute. . . . Ophiothyreus Ljungman, 1872. *goesi Ljung., 1872. Cuba. 200 fms. |
9 (8) |
No papillae skirting genital scales or radial shields. page 33 |
10 (11) |
Adoral shields entirely separated by the oral shield, not meeting within, 1 tentacle scale. |
10a (10b) |
Primary plates and radial shields large and conspicuous and, together with a radial series of plates, covering the entire disc; no granulation. . . . Ophioceramis Lyman, 1865. *Ophiolepis januarii Lütk., 1856. Caribbean. Littoral. |
10b (10a) |
Primary plates inconspicuous; radial shields the only large plates on dorsal side of disc, all other plates reduced to small scales, with fine granulation between them. . . . Ophiocrates Koehler, 1904. *lenta Koehler, 1904. Indonesia. 1,100 fms. |
11 (10) |
Adoral shields meeting on midline proximad to oral shield, 1 or 2 tentacle scales. |
12 (13) |
First lateral arm-plate conspicuously enlarged: 1 tentacle-scale: radial shields conspicuous, triangular, tumid, at the arm bases. . . . Ophiomidas Koehler, 1904. *alatus Koehler, 1904. Indonesia. 700 fms. |
13 (12) |
First lateral arm-plate not enlarged. |
14 (15) |
Marginal plates of disc greatly swollen, forming a rampart about the periphery: 2 tentacle scales. . . . Ophioteichus H. L. Clark, 1938. *parvispinum H. L. C., 1938. Tasman Sea (Lord Howe Is.). Littoral. |
15 (14) |
Marginal plates not swollen. |
15a (15b) |
Oral shield divided transversely into 1 proximal plate and 1 distal plate. Aboral side of disc covered by regularly arranged plates which carry tubercles. About 4 short, thick arm-spines. Oral papillae distinct, conspicuous. . . . Ophiocypris Koehler, 1931. *tuberculosus Koehler, 1931. Kei Is., 150 fms. |
15b (15a) |
Not so. |
16 (17) |
Disc covered with numerous small plates and scales, the larger ones surrounded by the smaller: radial shields small, widely separated by intervening plates and scales: three conspicuous plates lie between, and distal to, the shields: 4 or 5 short arm-spines: 2 tentacle-scales: dorsal and ventral arm-plates broadly contiguous throughout. . . . Ophiozona Lyman, 1865 (restr. Matsumoto, 1915). *Ophiolepis impressa Lütk., 1859. Caribbean. 50–200 fms. |
17 (16) |
Disc covered by a limited number of stout plates, including radial shields, and some smaller plates: 2 to 4 short arm-spines: dorsal and ventral arm-plates contiguous only at arm-base becoming progressively distant on the distal parts of arms. |
18 (19) |
Primary plates very conspicuous, covering the central half of disc: radial shields small, separated by three plates between and distal to them: 1 tentacle scale. . . . Ophiozonoida H. L. Clark, 1915. *picta H. L. C., 1915. New Zealand. Littoral. 50 fms. Ophiotylos Murakami, 1943, appears to fall very close to Ophiozonoida, differing mainly in having rudimentary arm-spines whereas there are 3 short arm-spines in Ophiozonoida picta. The type of Ophiotylos is O. leucus Murakami, 1943, Caroline Island. |
19 (18) |
Primary plates either conspicuous or not so, but not large: radial shields large, either contiguous, or separated by only a single narrow row of plates, not by 3 distal intervening plates: 1 or 2 tentacle scales. . . . Ophiozonella Matsumoto, 1915. *Ophiozona longispina H. L. C., 1908. Japan. 50–300 fms. page 34 |
20 (7) |
Dorsal arm-plates more or less sub-divided into supplementary plates or mosaic platelets. |
21 (24) |
Dorsal arm-plates quite distinct, but accompanied by a few supplementary plates. |
22 (23) |
Disc covered by irregular plates, not distinctly imbricating; usually small granules at or near the margins of the plates: radial shields small but distinct: primaries not distinct: one dorsal supplementary plate on each arm-joint, or on some arm-joints only. . . . Ophiolebella Mortensen. 1936. *Ophiolebes biscutifer E. A. Smith, 1879. Antarctic. 100 fms. The type-species was overlooked in H. L. Clark's (1915) Catalogue. |
23 (22) |
Disc covered by scales in two sizes, the larger surrounded by the smaller: radial shields conspicuous: 2 tentacle scales: smaller supplementary dorsal plates on either side of and/or distal to, the dorsal plates. . . . Ophiolepis Mueller & Troschel, 1840. *superba H. L. C., Indo-W. Pacific. Littoral. See H. L. Clark (1915), p. 342, for discussion on name of type-species. |
24 (21) |
Dorsal arm-plates profoundly modified by extensive fragmentation and intercalation of small mosaic platelets: radial shields very small and in-conspicuous. |
25 (26) |
Three or four tentacle-scales: dorsal arm-plates subdivided into two widely separated lateral halves, between which lies a mosaic of small platelets. Ophioplocus Lyman, 1861. *Ophiolepis imbricata M. & T., 1842. Indo-W. Pacific. Littoral. |
26 (25) |
One tentacle-scale: dorsal arm-plates subdivided into two lateral halves which are more or less widely separated at the base of the arm by a mosaic; but distally they lie close together, and one or two median plates intervene, or alternate, with them. Genital clefts not extending beyond the first arm-joint. . . . Ophioceres Koehler, 1922. *incipiens Koehler, 1922. Antarctic. 0–100 fms. |
27 (6) |
A single well-developed tentacle-scale on the basal 3 or 4 joints, but beyond this the tentacle-pores have no scale. Disc covered by a few large plates and scales: radial shields large, contiguous. . . . Amphipholizona H. L. Clark, 1915. *delicata H. L. C, 1915. Caribbean. 100 fms. |
28 (1) |
Tentacle-pores restricted to a few joints at the base of the arm. |
29 (30) |
Entire animal covered by thick smooth skin, more or less obscuring the plates: beneath the skin (and visible on its inner surface) are oval radial shields and other plates: dorsal arm-plates fragmented, comprising only thin, irregular fragments. . . . Ophiolipus Lyman, 1878. *agassizii Lyman, 1878. Caribbean. 100 fms. |
30 (29) |
Disc and arm-plates distinct, not obscured by skin: disc covered by porcellanous regular plates and radial shields: dorsal and ventral arm-plates minute, and not developed in the outer part of arm: lateral arm-plates meeting in dorsal and ventral midlines. |
31 (32) |
A continuous ridge of fused oral papillae round jaw-edge: two to five tentacle-pores. . . . Ophiomusium (s.s.) Lyman, 1869. Ophiomusa *ultima Hertz West Africa, Hertz 1927, established for spp. with only 2 pairs of tentacle-pores, is here regarded as falling within the definition of Ophiomusium. *eburneum Lyman, 1869. Caribbean. 200 fms. |
32 (31) |
Oral papillae distinct. . . . Ophiosphalma H. L. Clark, 1941. *Ophiomusium planum Lyman, 1878. Caribbean. 1,000 fms. |