TETHYS—AUSTRALASIAN. 99 
Aplysia tryonti MEINERTZHAGEN, Trans. and Proc. N. Z. Inst., 
1879, xii, p.271, 270 (1880).—Hurron, Tr. N. Z. Inst., xv, p. 118, 
_ pi. 18, fig. a (Dentition). 
The formula of teeth given by Hutton is 13:1:13, an unusually 
small number. In form, the teeth offer nothing especially charac- 
teristic. 
T. HAMILTONI Kirk. 
Animal about 7 inches in length, 23 inches high, and weighing 
14 oz. Color umber-brown, with fine irregular dark markings ; 
lighter below. Shell ear-shaped, horny, firm, ribbed on left side, 
irregularly concentrically striated ; epidermis bright straw color, 
highly polished. Inside white, with a pearly luster. Length, 1°6, 
breadth 1°45 inch. (kirk.) 
Napier, New Zealand. 
Aplysia hamiltont Kirx, Trans. N. Z. Inst., 1881, xiv, p. 283 
(1882). 
T. TASMANICA Tenison- Woods. 
Shell thin, fragile, translucent, shiny, obliquely subquadrate, 
Slenderly concentrically striate, and transversely minutely sulcate, 
subtestaceous within, slightly concave, enamelled, horny; apex 
scarcely incurved, with the upper margin arcuate and subreflexed, 
lower margin oblique and straight, anteriorly produced and rounded. 
Length 38, breadth 28 mill. (7.-W.) 
Tasmania. 
Aplysia tasmanica 'T.-W., Papers and Proc. and Rep. Roy. Soe. 
Tasm. for 1875, p. 156 (1876). 
A large form of taleous appearance, the margin becoming insensi- 
bly membranaceous. It is somewhat similar in form to A. gigantea 
of Sydney, but more oval, membranaceous, and smaller. (7.-W.) 
T. NORFOLKENSIS Sowerby. PI. 59, figs. 42, 43. 
Shell horny, brown, arched, ventricose, obliquely subovate, thin, 
smooth ; apex elevated, round, auriculated at the back ; upper mar- 
gin sloped, excavated; outer lip rather convex; lower margin 
rounded, dorsal margin arched, rounded, thinly reflected near the 
apex, obliquely inclined towards the lower end.  (Sowb.) 
“ Norfolk Island, New South Wales” (Sowb.) ; Shark Island, Port 
Jackson (Brazier). 
