MURICID. JEL 
tricose ; aperture wide; columella arcuated ; inner lip excavated, 
corrugated at the fore-part. P. planospira, Lam. (xliv, 18). 
THALESSA, H. and A. Adams. Spire elevated, whorls spinose, 
angulated at the upper part; aperture moderate; columella 
rounded, tubercular in front; outer lip nodulous internally. P. 
hippocastaneum, Lam. (xliv, 19). 
STRAMONITA, Schum. Spire elevated, whorls simple or nodu- 
lous; aperture moderate, produced anteriorly ; columella rounded, 
simple in front. P. Floridana, Conr. (xliv, 20). 
TROCHIA, Swains. Whorls separated by a deep groove; inner 
lip thickened, convex, striated ; aperture with a very short canal. 
P. cingulata, Lam. (xliv, 21). 
POLYTROPA, Swains. Spire acuminate, whorls foliated or tuber- 
culose; inner lip flattened; canal small, oblique; aperture 
narrowed at the fore-part. P.lapillus, Linn. (xliv, 22). 
crontIA, H. and A. Adams. Shell ovate; spire acuminated ; 
aperture moderate ; inner lip callous at the upper part; columella 
straight, simple anteriorly. P. amygdala, Kiener (xliv, 23). 
PURPURELLA, Bellardi, 1882. Aperture with a posterior canal, 
defined by callous margins. P.canaliculata, Bellardi. Tertiary ; 
Northern Italy. 
TAURASIA, Bellardi, 1882. Aperture canaliculate posteriorly, 
with callous margins; columella with an anterior plication. 
P. subfusiformis, d’Orb., and two other species. Tertiary ; 
Northern Italy. Neither this nor the preceding group possesses 
characters of much importance. 
[ SrnusIGERA, d’Orb. 
Syn.—Cheletropis, Forbes. 
Examples.—s. cancellata, d’Orb. (xx, 47). S. Husleyi, Forbes 
(ixxxvii, 13). 
Turbinate, imperforate, dextral or sinistral, with a smooth, 
striate or tuberculate surface and frequently, a keeled periphery ; 
aperture channeled in front, peristome thickened, reflected, with 
one or two claw-like lobes. 
The animal has four arms, arranged in cruciform manner and 
used for swimming. There are two tentacles, and the eyes, well- 
formed, are situated on the outer side of their bases. Respira- 
tory siphon short, being a simple fold of the mantle. Foot large 
and very mobile, furnished with a small, thin spiral operculum ; 
unprovided with a float. The dentition (xx, 48) has been sup- 
posed similar to that of the Muricidze—and the species have, 
consequently, been referred, as larval forms to that group. 
Dr. Jousseaume has established the identity of a species of 
Sinusigera with Purpura hemastoma, of which it is the larval 
form—his series of specimens of various ages, collected at Ben- 
guela, on the West Coast of Africa, showing a gradual develop- 
