210 52 



Corpus elongatum, gracile; notaen m processions brachioformibus vel limbo margi- 

 nali lato continuatum papillis non caducis praeditis. Rhinophoria perfoliata, tentacula 

 elongata; podarium angulis lentaculatim productis. 



Margo masticatorius mandibularis seriebus denticulorum instructus. Radula triseriata. 



Although the nudibranchiate Gasteropoda already some years ago were known to 

 such an extent and in such a way, that a systematic arranging might be attempted, the 

 given arrangement will be likely to prove only to be temporarily justified, as the discover- 

 ing of new forms that will not fit in with the given generic groups, will necessarily bring 

 many alterations in the provisional arrangement. 



Absolutely common to the different genera that have been put together in the 

 family Flabellinidae , is only the, elongated form of the body with the strong develop- 

 ment of the marginal part of the back, as also the rather long tentacles. With 

 the exception oï Calma they have all perfoliate rhinophores, and with the exception 

 oîSamla 1 ) they have all long foot-feelers. The latter genus shows also only one series 

 of denticles on the masticatory edge of the mandibles, while the other genera 

 have several series of such denticles. With the exception of Pteraeolidia , the radula 

 of which is uniserial, the others have three series of tooth-plates 2 ). In Mabdlina 

 and Calma the glans penis is armed with a sting, while in the other genera it is unarmed. 



The family, as established at present, contains the genera Flabellina, Calma, Samla, 

 and the present new one 3 ). 



Xossis, Bgh. N. Gen. 

 Notaeum limbo marginali lato. — Penis inermis. 



The genus is distinguished from the others by the thin conspicuous dorsal brim, 

 otherwise it seems to be rather nearly related to Samla, and as in this latter the penis 

 is unarmed, while by Samla the foot-feelers are wanting, and the masticatory edge of the 

 mandibles has only one series of denticles. 



Nossis indica, Bgh. n. sp. 

 PI. Ill, Figs. 11-12. 



Two specimens of this form were taken at Koh Kam on March 2 nd 1900, at a 

 depth of 30 fathoms. 



') R. Bergh, Ergebn. einer Reise nach dem Pacific (Schauinsland). Die Opistobranchien. Zoolog. 

 Jahrb. XIII, 3. 1900. p. 237. 



2 ) Three series of tooth-plates are also found in the distant genera Galvina, Capellinia, Hero, 

 Madrella. and in the Goryphellidae. 



3 ) voWtc, a Grecian poetess. 



