45 



numerous small cells, conglomerating especially around the efferent duct, probably represent 

 spermatids. The gonad itself is situated on the median line, at its distal extremity, which is 

 often curved to the left (at least in Pleuropus longifilis). Further information as to the anatomy 

 of this last form may be found in the paper of Gegenbaur ') ; I only mention the existence of 

 a gastric coecum, dorsally to the liver and not situated in it, and two insertions of the very 

 thin columellar muscle at the right side of the base of the terminal point, in which the shell 

 ends. The dorsal insertion is situated more proximally than the ventral one. 



Taking into consideration the questionableness of the true affinities of most of the young 

 stages, I have thought it better to discuss them separately, and not together with the adult forms. 



1. '^ Cleodora compressa"' Souleyet. (PI. II, fig. 64). 



1S50. Clio depressa Gray, Catalogue of the Mollusca in the collection of the British Museum, 



pit. II, Pteropoda, p. 14, (name only). 

 1852. Cleodora compressa Souleyet, Voyage de la Bonite, Zool , vol. II, p. iSi, pi. VI, figs. 26 — 32. 



Living animals: 



Stat. 203. 3°32'.5S., I24°I5'.5E. i spec. 



Stat. 220. Pasir Pandjang, West coast of Binongka. i spec. 



Stat. 282. 8°25'.2S., i27°i8'.4E. 2 spec. 



The shell as well as the animal shows much resemblance with Cavolinia trispmosa as 

 Pfeffer -) already suggested. Very likely it is the young stage of this species. It is useless, 

 to repeat the proofs of Pfeffer's opinion, as they have already been mentioned by Pelseneer ^). 



2. "■ Cleodora pyginaea' Boas. 



1886. Cleodora pygmaea Boas, Spolia atlantica, Bidrag til Pteropodernes Morfologi, etc., p. 84, 

 pi. 4, fig. 57, '^^■Jbis, pi. 5, fig. 90, pi. 4, fig. 50. 



Living animals : 



Stat. 36. 7° 38' S., 1 17° 31' E. 7 spec. 



Stat. jf-j. Sailus ketjil, Paternoster Islands. i spec. 



Stat. no. 4° 34' N., 122° o' E. i spec. 



Stat. 1 36. Ternate. 4 spec. 



Stat. 138. East coast of Kajoa Island. • i spec. 



Stat. 141. 1° o'.4 S., I27°25'.3E. 4 spec. 



Stat. 144. Damar Island. 13 spec. 



Stat. 165. Daram Island. 2 spec. 



Stat. \jf\ 2° 30' S., 1 29° 28' E. 9 spec. 



Stat. 185. 3° 20' S., I27°22'.9E. I spec. 



Stat. 194—197. i°53'.sS., i26°39' E.— i°45'.3S., I27°8'.3 E. 5 spec. 



Stat. 203. 3°32'.5 S., 124° 15'. 5 E. 14 spec. 



Stat. 205. Lohio Bay, Buton Strait. 2 spec. 



Stat. 245. 4° 1 6'. 5 S., 1 30" 1 5'. 8 E. I spec. 



This form, probably a young stage of Cavolitiia quadridetilala, "fills up a blank" as 



1) Unters. lib. Ptevop. u. Heterop. 1855, pi. I (Hyalaca coinplannlaj. 



2) Berl. Monatsber. 1879, p. 237. 



3) Chall. Rep. LXV, p. 87. 



