40 



5- Cavolinia gibbosa (Rang). 



1836. Hyalaea gibbosa Rang in: d"Orbignv, Voyage dans rAmérique meridionale, vol. V, 



p. 95, pi. V, figs. 16 — 20. 

 1836. Hyalaea flava d'Orbigny, Ibid., p. 97, pi. V, figs. 21 — 25. 

 1850. Cavolina gibbosa Gray, Catalogue of the MoUusca in the Collection of the British 



Museum, prt. II, Pteropoda, p. 8. 

 1850. Cavoli)ia fava Gray, Ibid., p. 8. 

 1880. Hyalaea gegenbauri Pfeffer, Die Pteropoden des Hamburger Museums, Abh. Naturw. 



Ver. Hamb. Bd. VII, p. 86, figs. 7— J^r. 

 1886. Cavolinia gibbosa Locard, Prodrome conchyliologie frangaise, p. 22. 



Empty shells: 



Only empty shells of this species have been found. I think that living animals rarely occur 

 in the tropics (see d'Orbigny ^), Boas '), Pelseneer ^), Munthe ^j, at least in the neighbourhood 

 of the equator. 



Several authors, among them .Souleyet ") and Benson "), have deplorably confused the 

 forms Hyalaea gibbosa Rang (= Hyalaea flava d'Orbigny) and Hyalaea gibbosa d'Orbigny 

 (= Hyalaea gegenbauri Pfeffer). Pfeffer "') has given an account of the different interpretations. 



The .Siboga-specimens agree in many points with the form jïai<a d'Orbigny. Very probably, 

 however, gradual transitions may be found to gibbosa d'Orbigny, and I can scarcely attach an)- 

 importance to the maintaining of the differences between these forms. 



Boas ") described a variety from the Indian Ocean ; I have seen specimens from this 

 region (32°S., 3i°E.) from the Leyden Museum, which agree with his figure, but the variety 

 was not found in the collection of the Siboga. 



i) Voyage d. rAmér. mér. vol. V, p. 96. 



2) Spolia atl. p. III. 



3) Chall. Rêp. LXV, p. 82—83. 



3) Ptevop. i Ups. Uq. Zool. Mus., Bih. t. K. Sveiiska vet-akad. Handl., Bd. 13, afd. IV, n" 2, p. 25. 



5) Voyage de la Bonite, vol. IT, p. 145. 



6) Ann. and. Mag. Nat. Hist., ser. III, 7, p. 23 — 24. 



7) Abh. Naturw. Ver. Hamb., p. 87. 



8) L. s. c, pi. 6, fig. 99(7. 



