54 
THE VOYAGE OF H.M.S. CHALLENGER. 
transverse grooves, which are closely approximated and equidistant like those of Clio 
striata. This cannot be regarded as teratological, for this species has been collected in 
different localities and in great abundance. Nor is it a young stage, for none of the 
observed specimens exceeded the size indicated. Clio chierchise differs notably from 
Clio striata in the absence of curvature on the shell, by the form of the embryonic shell, 
and by the form of the fins. 
Habitat. — Different localities near Panama (“ Vettor Pisani” Expedition). 
Subgenus Hyalocylix / Fol. 
1875. Hyaloeylis, Fol, Sur le developpement des Pteropodes, Archives d. Zool Exper., s4r. 3, 
t. iv. p. 177. 
Creseis (pars), Rang. 
Styliola (pars) auctorum (non Lesueur). 
Cleodora (pars), Souleyet, Boas, &c. 
Characters and Description. — Shell conical, slightly compressed dorso-ventrally 
(oval transverse section) ; the apex recurved dorsally ; the surface marked with trans- 
verse grooves from the well-marked constriction defining the embryonic shell on to 
the aperture. 
The animal has a conspicuous left tentacle ; the fin has a marginal non-muscular 
area, situated towards the dorso-lateral corner ; the posterior lobe of the foot is extremely 
short ; the aperture of the mantle as large as that of the shell. 
This “ subgenus ” includes only a single species. 
# 5. Clio (Hyalocylix) striata (Rang) (PI. II. fig. 3). 
1828. Creseis striata, Rang, Notice sur quelques Mollusques appartenant au genre Cleodora, &c., 
Ann. d. Sci. Nat., ser. 1, t. xiii. p. 315, pi. xv. fig. 7. 
1829. Creseis compressa, Eschscholtz, Zoologischer Atlas, Heft iii. p. 17, pi. xv. fig. 7. 
1830. Creseis zonata, Delle Chiaje, Memorie sulla storia e notomia degli animali senza vertebre, 
pi. lxxxii. fig. 9. 
1850. Styliola striata, Gray, Catalogue of the Mollusca in the Collection of the British Museum, 
pt. ii., Pteropoda, p. 18. 
1854. Creseis phxostoma, Troschel, Beitrage zur Kenntniss der Pteropoden, Archiv f. Natur- 
gesch., 1854, p. 206, pi. viii. figs. 5-7. 
For description and figures, I refer to Souleyet, Voyage de la Bonite, Zoologie, t. ii. 
p. 191, pi. viii. figs. 1-4. 
Observations. — I. In the preserved specimens the embryonic shell is almost always 
deciduous, so that this portion is hardly known. Fol alone 2 has figured it from young 
specimens. Having observed it on the living adults, I am able to give a more definite 
1 From vctkins, glassy, x.vkt%, cup. 
2 Sur le developpement des Ptdropodes, Archives d. Zool. Exper., s6r. 1, t. iv. figs. 2, 4. 
