NOTES ON A COLLECTION OF CALIFORNIAN NUDIBRANCHS. 33- 



Dorididae with plates, and will also deal with the Aeolididae. Even the . | 



preliminary diagnoses are models of lucidity, but I must confess that I j/o not ^ 

 at present see why a new genus is required for Monfereina, or why Hopkinsia 

 is separated from Idalia. 



Tritonia palmeri, Cooper. 

 PI. vii, figs. I, 2. 



Cooper: Proc. Calif. Acad. Nat. Sci., 1863, II. p. 207; Cockerell : 

 Nautilus, 1902, XV. p. 117. 



One small specimen from Dead Man's Island, San Pedro, found be- 

 tween tides. The notes on the living animal state that it was about 1 7 millim. 

 long, white, but strongly suffused with yellow dorsally. The back is des- 

 cribed as rugose with small warts. There were five or six " ramose branchial 

 lamellae " on either side. 



The alcoholic specimen is i o millim. long, nearly 5 broad, and 4 high. 

 It is very badly preserved and little can be made out of the external charac- 

 ters except that the shape is square and thick set, and that the oral veil bears 

 about 10 digitate processes. The tail is short and broad. 



The central nervous system is whitish and granulate, apparently much 

 as in T. Homhonji. The eyes are large and black ; the jaws are long, yellow- 

 ish with 4 — 6 rows of very strong and distinct denticles on the edge and a 

 mosaic pattern behind them. 



The formula of the radula is 36 x about 35. i. i. i. 35 as a maximum, 

 but many of the rows are considerably shorter. The median tooth (Fig. la.) 

 bears three very distinct thick cusps, that in the centre pointed, those at the 

 sides rounded. The first lateral (Fig. i/^)has a broad base, but is distinctly 

 hamate, the hook coming over the side of the median tooth. The remaining 

 laterals (Fig. 2) are rather straight and not very thick. Those near the out- 

 side are longer but the outermost are shorter. No armature was discovered 

 in the stomach. 



This form appears to be clearly distinct from T. tetraquetra, gigantea, 

 exsulans, and dlomedea recorded from the Pacific coast of North America 

 and to be allied to T. (Candiella) jile^eia and lineafa It is distinguished by 

 its coloration and the larger number of processes on the velum. The den- 

 tition appears to resemble that of T. lineafa rather than T. plehein, but the 

 teeth are not a very certain criterion in this genus. 



The genus Tritonia is recorded chiefly from the temperate parts, north- 

 ern as well as southern, of both the Atlantic and Pacific. Nearer the Equator 

 it appears to be replaced by Marionia, though its absence cannot be re- 

 garded as certain. Including the sub genus C'andiella, it contains about 24 

 species, some of which are doubtful. To the sixteen enumerated in Bergh's 

 System der Nudib. Gasteropoden, the following may be added : 17. T. dio- 

 inedt-a, Bergh. 18. T. exsulans, Bergh. 19. T. incerfa, Bergh. 20. T. austral it^, 

 Bergh. 21. jT. yiyantea, Bergh. 22. T. ingo/Hana, Bergh. 23. T. rillafranca, 

 Vayssiere. 24. T. ai>pendiadata, Eliot. Tritonia al/ni, described l)ut not fig- 

 ured, by Alder & Hancock, is a somewhat doubtful form. 



