Onchidtllti.} GASTROPODA. 813 



Jaw not seen. 



Radula having the formula 104+1+140. Median cusp of central 

 tooth elongated. The pleural teeth diminishing but little in size 

 toward the margin. 



Reproductive Organs. Vesicula seminalis small, tubular ; recepta- 

 culum seminis large, with a thick neck ; oviduct consisting of a thin 

 posterior and a much thicker anterior part, and where the two meet 

 the receptaculum seminis enters ; male organ long, with a small 

 posterior caecum containing calcareous concretions, which act as 

 stimulating papillae when the verge is exserted. 



Type in the Kgl. Museum fur Naturkunde, Berlin. 



. D'Urville Island, type (Finsch) ; Lyttelton Harbour (H. S.). 



6. Onchidella patelloides, Quoy and Gaimard, 1832. Plate 32, 

 fig. 4. 



Onchidium patelloides, Q. & G., Voy. Astrol., Zool., ii, 1832, 212, pi. 15, 

 f. 21-23 ; Dieff. N.Z., 247 ; Crit. List, 39. Perouia patelloides, Q. & G.. 

 C.M.M., 54. Onchidella patelloides, Q. & G., M.N.Z.M., 28. Oncidiella 

 patelloides, Q. & G. : Wissel, Zool. Jahrb., Syst., xx, 1904, 067, pi. 25, 

 f. 75-77 (animal, jaw, radula). 



Animal oval, Avith elevated back, margin more or less notched, 

 yellowish-brown, sometimes with blackish streaks, back with a number 

 of larger papillae, the remainder with fine granules. Tentacles rather 

 short, conic, brownish, with the eyes at their extremities. Sculpture : 

 A variable number of larger papillse are scattered over the notum, and 

 the rest is densely covered by smaller tubercles, extending to the 

 margin ; hyponotum finely wrinkled, the hyponotal line distinct. 

 Colour varying from yellowish-green to brownish, usually with patches 

 or streaks of dark grey or black ; the marginal glands are whitish, and 

 number 19 to 20; Quoy and Gaimard state their number to be 16, 

 their figure having 18 ; front of head blackish, rest of the under- 

 surface greyish-white. Anus under the tip of the tail, and close behind 

 it, in the median line, is the respiratory orifice. Hyponola in well- 

 preserved specimens nearly of the same width as the foot. Sole long, 

 pointed behind, smooth. 



Length over back, 26 mm. ; breadth, 17 mm. ; height, 8 mm. 

 Sole Length, 12 mm. ; breadth, 5 mm. 



Dentition. Hutton, T.N.Z.I., xiv, 155, pi. 4, f. B, R. 



Jaw dark brown, cutting-edge indented, curved laterally. Radula 

 having the formula 137+1 + 137. Central tooth broad, rounded in 

 front, tricuspid, the lateral cusps small. Pleural teeth with the inner 

 side concave, the inner cusp broad, the outer narrow and lightly curved. 



Reproductive organs those typical of the genus. 



Type in the Mus. Hist. Nat., Paris. 



Hob. North and South Islands of New Zealand ; Chatham Islands. 

 The type is from Astrolabe Bay. 



Maori. Pipiton (fide Quoy and Gaimard). 



