NOTES ON A COLLECTION OF CALIFORNIAN NUDIBRANCHS. 5 1 



around the orifice. In some of the present specimens the organ is exserted, 

 and it seems clear that there are four or five rows of round glandular 

 nodules at the base of the terminal portion, set about one third of the way 

 down the whole organ, which is very long. The circuit is interrupted in 

 one part by a triangular flap of skin which itself bears nodules. 



In this genus the denticles on the edge of the jaw are themselves 

 serrulate, and the central cusp of the teeth is serrulate on the under side, 

 both of which characters (though referring to somewhat minute details) are 

 unique in the hitherto described Aeoiidiadaf. Otherwise the Hennixxenda 

 is closely allied to Facelina and Facalana, and and perhaps the three should 

 be regarded as a single genus. The round glands on the verge recall those 

 found on the same organ in Facalana. 



Spurilla, Bergh. 

 This genus resembles Aeolidiella in its general shape and bilobed, 

 pectiniform teeth, but differs in having perfoliate rhinophores, though there 

 would seem to be a rudimentary perfoliation in some species of Aeolidiella. 

 For instance, Vayssiere states that the rhinophores of xie. <jlauca are " munis 

 d' un sillon spiral." Four species of Spurilla are known, namely : — 



1. Sp. neapolitana, (Delle Chiaje). 



2. Sp. san/a.^sirola, Bergh. 



3. Sp. inornafa, Vayssiere. 



4. Sp. cliromosoma, n. sp. 



Spurilla ehromosoma, n. sp. 



One specimen from Deadman's Island, San Pedro, where it is said to 

 be found on rocks between tides. According to the notes on the living 

 animal, the body is of a ruddy colour, with a row of white marks on the 

 back, the cerata greenish with white tips, and the oral tentacles remarkably 

 strong and large. It is mentioned that the cerata are easily deciduous, and 

 they are almost entirely lost in the preserved specimen. It is much bent, 

 but would be about 15 millim. long if straightened out, stoutly built but 

 with a long tail. Traces of the ruddy colour can be seen in tlie anterior 

 part of the body. The anterior corners of the foot are considerabiy pro- 

 duced but bent downwards. The oral tentacles are still unusually long and 

 stout. The short, thick, pinkish rhinophores bear about ten oblique per- 

 foliations. It is not possible to say what the arrangement of the cerata was. 

 The few that remain are very small. 



The buccal parts are everted, and the interior of tiie cavity is seen to 

 be covered with small tubercles. The jaws are yellow and no; denticles 

 could be found. I'lie radula consists of 19 yellow pectimform teeth, dis- 

 tinctly bilobed and arched, not flat. Hiere are one or two central denticles 

 lower than the rest, and on each side of them from 25 to 32 long, thin 

 lateral denticles, the points of which are often broken off. No genital armature 

 was found. 



