TETHYS-INDIAN OCEAN. 109 



Aplysia tigrina RANG, Hist. Nat. Aplys., p. 57, pi. 11. DESK., 

 Moll. Reun., p. 54. MART., in Mobius, p. 307. 



This is not the A. tigrina of Quoy & Gaimard, nor of Angas and 

 Sowerby. I do not know whether it is that of Deshayes and von 

 Martens or not. 



T. TIGRINELLA Gray. PI. 16, figs. 5, 6. 



Body elevated, greenish, very lucid, reticulated with brown, 

 with scattered spots and little lines of black. 



Because our individual, the drawing of which was made from the 

 living animal, offers some differences from that of Rang, we include 

 it here. Its length is six inches ; back very much swollen. The 

 swimming lobes smooth, always elevated, form a sinus extending 

 from behind the tentacles nearly to the tail. The foot is narrow, 

 the head short, and the tentacles are not much developed. The 

 ground color is a clear, diaphanous green, reticulated with spots of 

 bistre, in the midst of which are black dots or little lines. The 

 head is more regularly reticulated. 



The shell is broad, oval, a little concave, leathery, very finely 

 striated, with the beginning of a spire ; its edges are entirely mem- 

 branous. 



Port Louis, Mauritius. 



Aplysia tigrina QUOY & GAIMARD, Voy. de 1' Astro). Zool., ii, p. 

 308, pi. 24, f. 1, 2 (1832). A. tigrinella GRAY, Systematic arrange- 

 ment of the Figures, in M. E. Gray's Figures of Molluscous Ani- 

 mals, iv, p. 97, No. 27 (1850) ; referring to Vol. i, pi. 61, f. 4, copies 

 of Quoy's figures cited above. 



My information and figures, like Gray's, are derived entirely 

 from Quoy's account of this form. It differs strikingly from Rang's 

 A. tigrina in the shell (compare pi. 16, figs. 4 and 6), and there are 

 also differences in the soft parts. Quoy's figure from life shows 

 short finger-like processes scattered over the outer surface of the 

 swimming lobes, like a Notarchus, although his description men- 

 tions no such structure. The species appears, however, to be clearly 

 distinct from A. tigrina Rang, and the name proposed by Gray is 

 therefore adopted. 



T. NODIFERA Adams & Reeve. PI. 16, fig. 1. 



Dull olivaceous, covered with numerous rather distant elevated 

 tubercles ; painted with pale violaceous sparse spots, the foot orna- 



