22 ABT. 1. — CHAELES ELIOT: 



has priority over the latter (Bergh 1877) but whereas Bergh's 

 definition is clear and his type specimen well preserved, the 

 same cannot be said of Ehrenberg' s. His definition of the generic 

 characters (Apertura analis non tubulosa : pone branchiarum dis- 

 cum et ab eo plane discreta) does not apply to the specimen now 

 in the Zoological Museum at Berlin nor, it may be added, to any 

 known genus of Nudibranchs. Bergh (1. c.) came to the conclusion 

 that this specimen labelled Actinocyclus verrucosus was probably 

 of the same genus as his Sphaerodoris punctata but could not 

 establish the fact, as he was not allowed to dissect the animal. 

 I however was more fortunate and received permission to extract 

 the mouth parts and found that they have the typical characters 

 of Sphaerodoris. The labial armature is a thin band ( ? circular) 

 composed of small hooks. . The radula is at least 56x25 + 1.0.1 + 

 25 and perhaps much larger for the tissues are old and decay- 

 ed and it is possible that only the anterior half was extracted. 

 The first teeth of each row are as in Bergh's plate of Sph. laevis : 

 one half is smooth with a rudimentary hook, the other half bears 

 about 8 denticles. The other teeth are erect and bear 15 or more 

 denticles. But though the generic characters are certain the 

 specimens (two in number) are in such indifferent condition that 

 it is impossible to formulate their specific characters or to identi- 

 fy them with any species of Sphaerodoris already described. Also 

 there is some doubt as to the specific name : in the printed 

 edition of the Symbolae Physicae it is verrucosus : the jar in the 

 Berlin Museum is labelled Actinocyclus ocellatus, and Ehrenberg 

 seems to have also used the name papillosus. 



No specimens have been preserved of the two animals called 

 by Ehrenberg Actinocyclus velutinus and A. fragilis. They probab- 

 ly did not really belong to the same genus as his A. verrucosus. 



In favour of calling the genus Actinocyclus may be adduced 

 the weighty fact that the specimen so named by Ehrenberg in 

 1831 undoubtedly belongs to the same genus as the Spaerodork 

 created by Bergh in 1877. Against this may be set the follow- 

 ing considerations. (1) The specimen does not agree with Ehren - 

 berg's description and definition of the genus. Tt is possible that 



