50 



Family III. Cymbuliidae. 



1841. Cyuibulidae Cantraine, Malacologie méditerranéenne et littorale, Mém. Acad. Sci. Brux., 



vol. XIII, p. 33. 

 1853. Hyalidae (part.) d'Orbigny, in Ramon de la Sagra, Histoire physique, politique et 



naturelle de l'ile de Cuba, MoUusques, vol. I, p. 70. 

 1855. Cymbitliea Gegenbaur, Untersuchungen über Pteropoden und Heteropoden, p. 211. 

 1855. Cymbuliacea Troschel, Beitrage zur Kenntniss der Pteropoden, Arch. f. Naturgesch., 

 Jahrg. XX, p. 210. 

 Hyalaeidae (part.) Auctorum. 

 1885. Alata Wagner, Die Wirbellosen des Weissen Meeres, Bd. I, p. 119. 

 Cymbidiidae Auctorum. 



ThoLigh representatives of this family have been knovvn for a long time, the truc 

 affinities of the Cymbuliidae were only recognised by Pelseneer ^), according to whom the 

 Cymbuliidae are not to be regarded as specialised Cavoliniidae (an opinion shared bv the few 

 authors who had an opinion of their own on this point), but "have descended from Limacinoid 

 ancestors". Aniong the Limacinidae it is the genus Per ac lis with which the Cymbuliidae (and 

 especially the larvae) show the closest phylogenetic affinity. 



As to the systematic relation of the group, the thorough revision of genera and species, 

 made by Pelseneer "), has thrown some light on the chaos of names, generally applied to forms 

 which had been described in an insufficiënt manner. Two circumstances have especially contributed 

 to the incompleteness of our knowledge about the species, belonging to the family. In the first 

 place the "shell" of the Cymbuliidae is very readily lost, the consequence of which is that 

 species have been described as naked which in reality possess a "shell", and on the other hand 

 some descriptions of species have been based on the examination of empty "shells" only, without 

 animals. But in addition to this, the young forms of the Cymbuliidae differ greatly from the 

 adult animals, the result of which was that several larvae were regarded as distinct species. 



Taking these facts into consideration, it becomes obvious that new genera and species can 

 only be established when the material at command is very complete, and shells with the animals 

 i)i sitit can be observed, so that no doubt can arise as to animal and shell beloneine toeether. 



The Siboga Expedition has brought home many Cymbuliidae, the greater part of which, 

 however, are certainly young forms without shells. Little desirous to increase the number of 

 incompletely known species, I shall abstain from describing such forms as "new" species, about 

 which I am unable to give a complete diagnosis. 



Whereas after the publication of Pelseneer's work the systematic relations of the 

 Cymbuliidae to each other have undergone some alterations, I shall tr\- to give again a revision 

 of the various genera and species of the Cymbuliidae. 



The oreneric names are the following- : 



Argivora Lesueur. Cymbulia Péron et Lesueur. Dcsiiiopterus Chun. Tiedcinannia Delle Chiaje. 

 Corolla Dall. Cymbziliopsis Pelseneer. Gleba Forskal. 



1) Challenger Report, LXVI, p. 31 — 32. 



2) Challenger Report. LXV, p. 93 — 96. 



