Royal Mic7'osco]pical Society. 143 



outer surface at its antero-clorsal extremity. It contains a mass of 

 dark yellow granules, which is kept continually revolving by means 

 of the strong cilia which line its internal surface ; the walls of both 

 these chambers are thick, and appear to be glandular, especially 

 those of the stomach. A peculiarity which distinguishes this ap- 

 pendicularia from all others is, that the anus opens behind instead 

 of in front of the attachment of the appendage, 



A pair of ciliated branchial openings exist near the anterior 

 end of the body, which are situated one on each side of the wider 

 part of the pharynx ; these openings were described by Gegenbaur * 

 as leading into a series of internal channels, but Professor Huxley f 

 demonstrated that they opened directly into the branchial cham- 

 ber ; in the present subject they appear to be simple ciliated pits, 

 and I could make out no communication between them and the 

 pharynx (for there really is no branchial chamber). Unfortunately 

 I omitted to feed the animals with indigo ; perhaps if I had done 

 so the connection between the two might have become more appa- 

 rent ; the cilia of the structures in question are very large, and are 

 so curved that all the points meet in the centre. 



The endosfcyle which Professor Huxley % considered to be the 

 optical expression of a fold of the branchial chamber, here appears 

 to be rather a complicated structure ; on a dorsal view (Fig. 2) it is 

 seen to be of an oval figure with the posterior end truncate ; its 

 external walls are thick, and internally it is occupied by what 

 seems to be a hollow cavity, which is divided into two by a longi- 

 tudinal partition, while anteriorly and posteriorly two small spaces 

 are left, the latter of which is truncate like the external wall ; on a 

 side view (Fig. 1) the shape is totally different, it now appears to 

 have a crescentic form, with external thick granular walls lined 

 internally by a thin layer of a bright substance ; again, in another 

 specimen, when seen in a position between those two, it looks like a 

 conical body capped anteriorly by a kidney-shaped mass. Whether 

 this diversity of appearance is due to a change of position simply, 

 or to individual variations in different subjects, I am not prepared 

 to say, but the probability is that it is due to the latter cause, 

 considering the modifications to which the external tunic is subject. 



A very distinct vesicle containing an otolithe is present im- 

 bedded in the thickened ventral wall of the anterior part of the 

 body ; this is surrounded by a granular nervous mass from which 

 a nerve could be traced running along the pharynx towards its 

 posterior extremity, but I failed to discover in this species the 

 extensive nervous ramifications described by Dr. Moss, § neither 

 was the ganglionic chain running along the appendage apparent. 



In many specimens a curious pyriform body was found attached 



* Loc. cit. t 'Qnar. Jour. Mic. Sci.,' vol. iv., 18.56. 



X Loc. cit. § Loc. cit. 



M 2 



