TETHYS-POLYNESIAN. 95 



This small sized species is especially remark able for its short form, 

 extremely swollen back, acute tail and short anterior portion. The 

 foot is very broad and spreading in front, thick and rugose. The 

 swimming lobes are narrow and close on the back, and do not cover 

 it entirely. The opercle or mantle is quite large and oblong. 



T. PEASEI Pilsbry, n. n. PI. 25, fig. 2. 



Animal oblong, slender, smooth, dorsal region much elevated, 

 convex in outline, gradually sloping posteriorly to the termination 

 of the foot, anteriorly abrupt ; neck long ; cervical tentacles slender, 

 long and cylindrical; labial tentacles large, moderately dilated. 

 Siphon large, erect. Color pale fawn, mottled with darker, and 

 covered with minute crowded white and very light purple dots ; 

 under portion of the body, edges of the mantle and labial tentacles 

 margined with dark slate color. (Pse.). 



When in confinement it adhered with considerable tenacity to the 

 jar by the hinder portion of the foot. (Pse.). 



Huahine, Society Is. (Pse.). 



Syphonota punctata PSE., Amer. Journ Conch., iv, p. 77, pi. 9, f. 2 

 (1868). Not Aplysia punctata Cuvier. 



The size is not stated by Pease, but judging from his figure it is a 

 small, long-tailed form with long excurrent siphon. The shell is 

 undescribed. 



T. KERAUDRENII Rang. PL 39, figs. 1, 2, 3, 4. 



Length 15 cm. Oblong, very much swollen, not much elongated 

 forward, acute behind ; swimming lobes very large ; opercle [mantle] 

 vast, oblong, with a very distinct tube in the middle ; the siphon 

 long and open lengthwise. Smooth and greenish-brown with large 

 irregular and close black spots. Anterior tentacles wide with wavy 

 borders, posterior tentacles conic. 



Shell large, oval, not very concave, elongate, much narrowed be- 

 hind, the sinus long and rather shallow ; apex triangular, recurved 

 and thick ; calcareous layer quite thick. Color brown-yellow above, 

 white below. Length 48 mill. 



Tahiti (Otaheite), Society Is. (Lesson). 



Aplysia keraudrenii RANG, Hist. Nat. Aplys., p. 59, pi. 13. LES- 

 SON, Voy. autour du Monde, etc., La Coquille, Zool., ii, pt. 1, p. 294. 

 Not Syphonota keraudreni ANGAS, P. Z. S., 1867, p. 228. 



