The G. Typhlonarke was established by Waite (1909) to contain T. aysoni (Hamilton 1902). originally placed in the G. Astrape but distinct in the form of the disc, junction of the disc and pelvics, the absence of functional eyes, and the short tail. Phillipps (1929) recognized a second species, oval in form and remarkable in the absence of a dorsal fin. In 1949, Phillipps states that a specimen taken on a "foul hook" at 130 fathoms in Cook Strait had a dorsal fin. Examination of the type in the Dominion Museum shows a definite scar at the site of the dorsal. Phillipps also states, on the evidence of Professor B. J. Marples, that both species occur off Otago Heads. Hamilton's original account actually includes both species, but clearly a specimen of T. aysoni as recognized by Waite (1909) was the first examined and is the basis for the species. This specimen is shown in Plate XII, Fig. B. The other figures in Hamilton's paper refer to T. tarakea. The confusion of the two species rests in the absence of functional eyes and the form of other striking features which apparently detracted attention from the quite definite distinctions between the two. Both species are blind, shallow water, obviously benthic, and with quaintly modified pelvics; but T. aysoni is circular in outline, the margin of the disc is thin, and the claspers do not reach beyond the margin of the disc. T. tarakea has an ovoidal disc with a heavy thick rim, and the claspers are visible in dorsal view. Other features common to both species, and not mentioned page 2 page 3 by Waite in his generic description, are: the rostral cartilage, short and reduced to a median portion only; the anterior edge of the disc supported by greatly enlarged preorbital cartilages: the cranium lacks a formed orbit: the pectoral girdle extends as a complete ring around the vertebral column; on each side of the head there is a large electric organ, hounded medially by the trunk muscles and laterally by the propterygial elements: the columns forming the electric organ are very large, there being only 180 to 200 columns in each organ (Torpedo marmorata has about 450 columns per organ). Waite (1909) and Phillipps (1929) state that the eye is lacking in Typhlonarke though an optic nerve persists. Dissection of a number of specimens of both T. aysoni and T. tarakca shows (Plate 1, Fig. J) that the eye and optic nerve are present in both species, though the eye is not visible externally, being some 2.0 mm. under the surface of the skin in the subcutaneous fascia. Very delicate fibres inserted on the eyeball apparently represent vestiges of the ocular muscles.