84 



easily understand the mistake of most zoologists (before Boas and Pelseneer) who considered 

 these animals as testaceous, and therefore classed them among the Thecosomata. 



As to the characters of the family, I may refer to Boas ') and Pelseneer -). Some 

 inaccuracies of Boas, who mistook the buccal ajjpendages as most authors did before 

 him, were rectified by Pelsexeer. I must, however, protest against one statement of both 

 authors, viz. that the posterior lobe of the foot is separated from the fins, as in all 

 Gymnosomata. I have examined a large number of specimens, but I always found this posterior 

 lobe connected with the fins (PI. VI, fig. 153,//)- In this respect I agree with Huxley ^^ 

 and Souleyet''). 



HalOpSyche Bronn. 



1825. Psyche Rang, Description d'uii nouveau genre de Ia classe des Ptéropodes, Ann. d. 



Sc. Nat., sér. i, vol. Y, p. 284. 

 1827. Eiiribia Rang, Description de deux genres nouveaux, appartenant a la classe des 



Ptéropodes, Ann. d. Sc. Nat., sér. i, vol. XII, p. 328. 

 1832. ? Cyrnbulia (part.) Quoy et Gaimard, Voyage de TAstrolabe, p. 376. 

 1856. Eurybia Woodward, A Manual of the Mollusca, p. 206. 



1862. Halopsyche Bronn, Die Klassen und Ordnungen des Thierreichs, Bd. III, p. 645. 

 1862. Thcceurybia Bronn, Ibid., p. 645. 



From the description and figures of OuoY and Gaimard who described a "■ Cymbttlia 

 norfolkensis'\ it is impossible to decide to which form these indications must be applied. Most 

 probably a species belonging to the genus in question is meant. 



At present only one spjecies is sufiiciently well known, which has been collected in 

 considerable quantities by the Siboga Expedition. As to the forms PsycJic globitlosa and 

 Euribia JicDiispherica, both described by Rang, we know too little about them as to express 

 any opinion regarding their systematic position, but it would be very interesting to obtain 

 further Information, as the fins in these animals attain excessive development. 



I. HalopsycJic gaiidichaiidi (Souleyet). (PI. VI, figs. 153 — 156). 



1852. Euribia gaudichandii Souleyet, Voyage de la Bonite, vol. II, p. 253, pi. XIV, figs. i — 6. 

 1859. Eurybia gaudicliaudi Macdonald, On the anatomy of Eurybia gaudicliaudi, Transac. 



Linn. Soc. Lond., vol. XXII, p. 245, pi. XLIII. 

 1883. Thcceurybia norfolkeiisis Ray Lankester, Mollusca, Encyclop. Brit., 9"' Ed., vol. XVI, 



p. 666, fig. 83. 



1886. Halopsyche gaudichandii Boas, Spolia atlantica, Bidrag til Fteropodernes Morfologi etc, 



K. Dansk. Vidensk. Selsk. Skrift., 6 Raekke, Bd. IV, p. 173, pi. VIII, fig. 119. 



1887. Halopsyclic gaudichaudi Pelseneer, Chall. Rep. 'LVIII, p. 55, pi. III, figs. 7 — 9. 



Living animals: 



Stat. 141. 1° o'.4 S., I27°25'.3E. 28 spec. 



Stat. 143. 1° 4'. 5 S., i27°52'.6E. 3 spec. 



1) Spolia atlantica, p. 171 — 173. 



2) Chall. Rep., LVIII, p. 52 — 53. 



3) On the Morphology of the cephalous Mollusca, Philos. Transact. (1S53), pi. IV, fig. 3. 



4) Voyage de la Bonite, vol. II, pi. XV, fig. i. 



