OF CONCnOLOGY. 147 



11. F. SPINIGER, Conr., Journ. Ac. N. S., Phil., n. s. i., (1849,) 



p. 207. 

 Fusus sjnniger, Conr. op. cit., i., (1848,) p. 117, pi. ii., f. 32. 



" Oligocene." — Vicksburg, Miss. 



12. F. NODULATUS, Conr., op. cit., i., (1849,) p. 207. 



' ' Oligocene. ' ' — Vicksburg. 



Sycotypus, Gill ex Browne. 



= Sycotypus, Browne, Nat. Hist. Jam., 1756, p. 406, [canali- 



culatus.) 

 > Pyrula, Petit., Journ. Conch., 1852, p. 142, 144, {canalicula- 



tus.) 

 Pyrula, sp. Lam., &c., Busycon, sp. Morch, Ad. f., Stimpson, 



&c. 



Etym. Huxou, fig. ; vjtto:;, form. 



Type. — jS. canaliculatus. 



Animal rather small, retractile, with its operculum within the 

 shell for about a third of a volution from the aperture, lladula 

 with the rachidian tooth 3-dentate ; lateral 4 — 5-dentate (*S'. 

 canaliculatus, S. pyrum, fide Stimpson.) 



Operculum with the nucleus apical. 



SJiell with a ciliated periostraca ; with little raised revolving 

 lines ; pyriform ; the whorls wound tightly round the axis, 

 leaving no umbilicus, angular behind, with the surface shelving 

 towards the angle ; below the angle ventricose and thence 

 gradually contracted and terminating in a moderately elongated 

 canal (generally somewhat shorter than the aperture) concurrent 

 with and adjoining the siphonal fasciole, and correspondingly 

 tortuous ; spire variable in evolution, with a papillary nucleus; 

 suture canaliculated ; siphonal fasciole coincident with the colu- 

 mellar fold ; aperture rhombo-ovate ; outer lip in youth striated 

 within ; columella covered with a thin callous coat, decidedly 

 concave, and with a wide marginal fold. 



The genus Sycotypus is extremely closely related to Fulgur, but 

 the living species are constantly distinguished by the associated 

 characters of a canaliculated suture and a ciliated periostraca. 

 Tlie extinct species of the same form having a channelled suture 

 may be inferred to have possessed tlie same association of charac- 

 ters ; some slight difference exists, however, in the solidity of the 

 shells and especially in the armature of the angle which has in- 

 duced Dr. Stimpson to believe that the indications as to generic 

 differentiation afforded by the recent species are contradicted, 

 and it must be admitted that there is a very wide difference be- 



