51 



The genus Argivora was based by Lesueur on a small mollusc, first described by him ') 

 as a naked Cymbulia-^ he called it Cymbtilia parva, but proposed to erect for this form the 

 new genus Argivora. The species has never been figured, and its description is very incomplete. 

 Perhaps it is a small specimen of Cymbntiopsis, but absolute certainty cannot be obtained. 



Corolla was established by D.vll ") on a small specimen (Corolla spcctabilisj; the genus, 

 though very nearly related to Tiedeiiiatinia, differed from it in the pendant body and absence 

 of a shell. The genus Corolla was declared by Pelseneer ■^) to be synonymous with Gleba. 

 But Dall *) himself afterwards adknowledged the identity of Corolla with Cy»ibuliopsis. 



Cymbtilia of Peron et Lesueur '") includes the species on which the whole family has 

 been based. Cymbulia pcroni from the Mediterranean is very well known and distincruished 

 from other forms by a whole series of characters. The genus Cymbulia has therefore every 

 right to exist. 



The genus Cymbtiliopsis was proposed by Pelseneer ") to receive some forms, formerly 

 described as species of Cymbulia. Although the species of Cymbnliopsis resemble Gleba more 

 than Cymbulia (the name Cymbuliopsis therefore being not very well chosen), yet there are 

 some characters which justify the existence of Pelseneer's genus. 



The form for which the genus Des7nopterus has been erected ^), seemed to exhibit such 

 marked differences from any other "Pteropod", hitherto known, that the discoverer who regarded 

 his Dcsmopterus papilio as a Gymnosomatous "Pteropod", established a new family Desmopteridae 

 for it. The description and figures, given by Chun, both of the external form of Desmoplertis 

 papilio and of its anatomy, support, however, strongly the belief that this species belono-s to 

 the Cymbuliidae, an opinion, already expressed by Pelseneer ^). I have had occasion to prove 

 the truth of the suggestion of this last author, as a species of Desmoptertis was also found 

 in the -Siboga-material (Stat. 169, West coast of New-Guinea). 



The only specimen (PI. Ill, figs. 80 — 81) very much resembles Desinopter us papilio, 

 but I have seen no pigment spots on the fins nor on the filiform appendages, which are rather 

 short. In every other respect this specimen is so very much like the animal of Chun that it 

 is recognised at first sight as a Dcsmopterus. 



As to the anatomy, after having made a series of transverse sections of the Siboo-a- 

 specimen, I agree with Chun in almost every respect. The radula, however, consists of three 

 longitudinal series of teeth; in a transverse row, so there are three teeth; this fact does not 

 correspond with the words of Chun') "etwa 20 — 30 Zahnchen sind in jeder Ouerreihe nach- 

 weisbar", and it procures an argument the more in favour of Pelseneer's opinion. It has 

 become obvious by the explanations of this last author: 



1) In DE Blainville, Manuel de Conchyliologie, p. 655. The few words of de Blainville are the only information we possess 

 about this species. 



2) Description of sixty new forms of Molluscs., etc. Americ. Journ. Conch, vol. VH, p. 137. 



3) Challenger Report. LXV, p. 103. 



4) Nautilus in, p. 30 — 32, 1889. 



5) Ann. Mus. d'Hist. Nat. t. XV, p. 69, iSio. 



6) L. s. c. p. 100. 



7) Chun, Bericht Uber eine nach den canarischen Inseln ausgefiihrte Reisc, Sitz. Ber. Berl. Akad., 18S9. vol. HI, p. 540 546. 



8) Sur la position systematique de Desmoptcrus papilio Chun, Zool. Anz., vol. XII, p. 525 — 526. 



9) L. c. p. 541. 



