1906.] OF SOUTHERN INDIA AND CEYLON. 663 



DOKIDOPSIS CLAVULATA A. & H. 



(A. & H. 1. c. p. 127. Eliot, Proc. Zool. Soc. 1904, ii. p. 278.) 



Three specimens in a fair state of preservation. Though the 

 animal has a general resemblance to Doridopsis denisoni, it would 

 seem to be easily distinguishable from it externally. The margin 

 of the branchial pocket is much more distinctly tuberculate, and 

 the large dark green areas on the back are veiy plain. 



There also seem to be difierences in the genitalia. They are 

 much hardened, but it is clear that the vas deferens is much 

 shorter than in D. denisoni and not so elaborately coiled. The 

 lower part of the vas deferens and the penis are thickly covered 

 with small, slightly bent, yellowish spines. 



The arrangement of the alimentary canal, so far as it can be 

 still ascertained, is as in D. denisoni. A large double mouth- 

 gland lies beneath the buccal mass and opens into it by a single 

 duct. There is a constriction after the proboscis, and another 

 about halfway between the proboscis and liver. 



Doridopsis (?) grisea (Kelaart). 

 (Kelaart, 1. c. p. 297.) 



The statement that the " mouth is surrounded with a white 

 veil " makes it probable that this species is a Doridopsis. Kelaart 

 uses a similar expression concerning D. carhuncidosa ; and it is 

 evidently an attempt to describe the two small tentacles cha- 

 racteristic of the genus which a,re often attached for the greater 

 part of their length and inclined towards one another above the 

 poinform mouth. 



D. grisea is possibly the same as the animal figured by Bergh 

 in the Opisthobranchia of the ' Siboga' Expedition, plate v. fig. 19, 

 as " Doriop)sis ? " 



DoRiOPSiLLA Bergh. 



(See Bergh, Jahrb. d. Deutsch. malak. Gesell. 1880, pp. 20-30 ; 

 id., Zool. Jahrb., Abth. fUr Syst., Jena, 1896, Band ix. 

 Heft iii. pp. 454-8 ; and Yayssiere on Doriopsilla areolata in 

 'Talisman' Opisthobranches, 1902, pp. 235-7, and Opist. 

 de MarseiUe, iii. 1901, pp. 50-52.) 



In Doriopsilla the dorsal surface is granulate and harder than 

 in Doridojjsis ; but the chief difference between the two genera 

 is that whereas in Dorioptsilla the buccal ganglia beneath the 

 alimentary tube lie immediately behind the main body of the 

 central nervous system, in Doridoi^sis they lie at some distance 

 behind it on a constriction of the alimentary tube, and are united 

 to the nerve-collar by rather long connectives. 



The difference may seem slight, but is of considerable structural 

 importance, as will perhaps be understood by an inspection of 

 figs. 4-7, PI. XLYIL, which give comparative views taken from 

 beneath and fi-om the side of the central nervous system and 



