REPORT ON THE HETEROPODA. 
23 
Of this species there are two males and two females in the Challenger collection, 
obtained on the 3rd of March 1876, at the surface, in the South Atlantic Ocean. One of 
the females is remarkable for the length of the filiform appendage, 1 at the end of the 
short caudal prolongation being considerably longer and more thread-like than that figured 
by Eydoux and Souleyet (Yoy. “ Bonite,” pi. xvi. fig. l). In the other specimen it is 
altogether wanting, its absence doubtless being due to accident. The male examples 
have much the general aspect of the females, but are at once recognised by the presence 
of tentacles and the genital organs behind the nucleus. This portion of the animal is 
fairly like the representation of that of Firoloida lesueuri (op. cit ., pi. xvi. figs. 5, 6, 7), 
but the narrow prolongation or caudal extremity is not so distinctly jointed as 
depicted in the figures. Neither of the females have a sucker on the fin, but it is 
present in both males. The egg-tube of one of the specimens is 10 mm. in length, 
and of precisely the same construction as that figured by Troschel ( Firoloida gracilis). 
It contains between four hundred and four hundred and fifty ova packed together 
apparently without any definite arrangement. 
Firoloida lesueurii (d’Orbigny). 
1836. Firola (Cerophora) lesueurii, d’Orbigny, Voy. Anier. mfirid., vol. v. p. 151, pi. x. 
figs. 11, 12. 
1841. Firole cle Lesueur, Eydoux and Souleyet, Voy. “Bonite,” Atlas, pi. xvi. figs. 5-7. 
1850. Pterotrachea ( Firoloida ) eydouxii, Gray, Fig. Moll. Anirn., vol. iv. p. 100, pi. ccxxxviii. 
fig. 2 (copy of Eydoux and Souleyet). 
1850. Cerophora lesueurii, Gray, op. cit., pi. lxii. fig. 4 (copy of d’Orbigny). 
1852. Firoloida lesueurii, Souleyet, Voy. “Bonite,” Zool., vol. ii. p. 343. 
1853. ,, „ Verany, Journ. de Conchyl., vol. iv. p. 381. 
1854. Firoloides lesueurii, Leuckart, Zool. Untersucb., Heft. iii. pp. 3-68, pis. i., iL 
1855. Firoloidea eydouxii, H. and A. Adams, Gen. Moll., vol. ii. p. 95. 
1855. „ lesueurii, id., loc. cit., p. 95, pi. lxix. fig. 8 (copy of d’Orbigny). 
1858. Firoloides lesueurii, Owen, Ency. Brit., vol. xv. p. 378, fig. 71. 
1866. Firoloidea lesueurii, Keferstein, Bronn’s Thierreich, vol. iii. pt. 2, pi. lxix. fig. 8 (reduced 
copy of Eydoux and Souleyet). 
Habitat. — Indian and Atlantic Oceans (Eydoux and Souleyet). 
A comparison of d’Orbigny ’s figures and description with those of Souleyet will show 
considerable differences in several points. This I presume induced Gray and the Messrs. 
Adams to believe that two distinct forms were indicated. However, as most likely 
d’Orbigny’s figures and his account of this animal are more or less defective, it seems 
probable, or at all events possible, that Souleyet was right in associating his specimens 
with this species. 
1 Fol (Arch. d. Zool. Expdr., 1876 , vol. v. p. 107 ) erroneously states that Firoloida has no filiform appendage. It 
was described and figured by Souleyet in 1852 , and again by Macdonald in 1862 . 
