16 
THE VOYAGE OF H.M.S. CHALLENGER. 
Pterotrachea hippocampus, Philippi. 
1829. Pterotrachea hyalina, Chiaje, Mem. Stor. Anim. senza Vert., vol. iv. pp. 183, 198, pi. xlvii. 
fig. 13. 
1829. „ frederici , Chiaje, loc. cit, pp. 184, 198, pi. lxix. fig. 2. 
1836. „ hippocampus, Philippi, Moll. Sicil., vol. i. p. 242; vol. ii. p. 204, pi. xxviii. 
fig. 16. 
1841. ,, frederidana, Chiaje, Deseriz. e Notom. Anim. Invert. Sicil., vol. ii. p. 93. 
1843. „ frederici, id., Rendicont. Accad. Sci. Soc. Borbon. Napoli, vol. ii. p. 106. 
1850. „ frederica (part.), Gray, Fig. Moll. Anim., vol. iv. p. 100, pi. clvii. fig. 2 (copy 
of Chiaje). 
18^0. „ hyalina, Gray, loc. cit., pi. clvii. fig. 3. 
1850. „ hippocampus, Gray, loc. cit., pi. civ. fig. 5 (copy of Philippi). 
1855. „ „ H. and A. Adams, Gen. Moll., vol. ii. p. 94, pi. lxix. fig. 7 
(copy of Philippi). 
1855. „ hyalina, H. and A. Adams, loc. cit., p. 94. 
1855. ,, ,, Gegenbaur, Untersuch. Pterop. und Heterop., p. 215. 
Habitat. — Mediterranean. 
In placing with this species Pterotrachea frederici and Pterotrachea hyalina of 
Chiaje, which are evidently distinct from the species described under those names by 
Lesueur and Forskal respectively, I have followed Philippi. 
Pterotrachea quoyana (d’Orbigny). 
1836. Firola quoyana, d’Orbigny, Voy. Amer. merid., vol. v. p. 150, pi. xi. figs. 1, 2. 
1850. Pterotrachea quoyana, Gray, Fig. Moll. Anim., vol. iv. p. 100, pi. lxii. figs. 1, 1 a (copy of 
d’Orhigny). 
1855. „ ,, H. and A. Adams, Gen. Moll., vol. ii. p. 94. 
1859. „ „ Chenu, Man. Conch., vol. i. p. 123, fig. 536 (after d’Orhigny 
reversed). 
1883. Firola quoyana , Tryon, Struct. Syst. Conch., vol. ii. pi. lxxxvi. fig. 97 (copy of d’Orhigny 
reversed and reduced). 
Habitat. — South Atlantic (d’Orbigny). 
Pterotrachea edwardsii (Deshay es). 
1836-1846. Firola edwardsii, Deshayes, Cuvier’s Regne Anim. Moll., pi. xxxix. fig. 1. 
1850. Pterotrachea edwardsii, Gray, Fig. Moll. Anim., pi. clix. fig. 2 (copy of Deshayes). 
1855. „ ,, H. and A. Adams, Gen. Moll., vol. ii. p. 94. 
Habitat. — Mediterranean (Deshayes). 
Pterotrachea umbilicata, Chiaje. 
1841. Pterotrachea umbilicata, Chiaje, Deseriz. e Notom. Anim. Invert. Sicil., vol. ii. p. 94 
pi. lxiv. figs. 12-14. 
1843. „ „ id., Rendicont. Accad. Sci. Soc. Borbon. Napoli, vol. ii. p. 107. 
Habitat. — Mediterranean. 
