1921] NATURAL SCIENCES OF PHILADELPHIA. 361 



In three peculiar specimens with hypertrophic ventral callus 

 the width exceeds the length. They occurred in a series of 25 normal 

 adult shells. 



Cassis (Cypraecassis) testiculus (L). 



Cypraecua.sis k'uliculu.'i Gabb, Tr. Am. Philos. Soc. xv, 1873, p. 222. 

 Three rather small specimens 33 to 35. 5 mm. long. In one the 

 spiral grooves appear only around the base, the axial folds being 

 smooth. 



Cassis inflata monilifera Guppy. 



Cassidea granulosa Gabb, Trans. Amer. Phil. Soc, xv, 222, 1873. 

 Cassis monilifera Guppy, Quar. Jour. Geol. Soc, xxii, 287, pi. 17, fig. 8. 



This form is almost exactly intermediate between C. inflata 

 granulosa of the Antillean fauna and C. ahbreviata of the Panamic 

 region, and may well have been their common progenitor. It has 

 the somewhat coronated whorls of ahbreviata, there being two 

 prominent granose spirals at the shoulder. The rest of the body- 

 whorl, in the Santo Domingo shells, is granose at the intersect- 

 ions of narrow vertical folds with the spirals, in small examples, vary- 

 ing to nearly free from longitudinal sculpture in some large ones; and 

 irregularly plicate but not granose in others. The smooth embryonic 

 shell is perhaps a little smaller and shorter than in the Pacific C. 

 ahbreviata, similar to that of C. granulosa. 



Sconsia laevigata (Sowerby) 



Cassidaria Icevigata Sowb., Quart. Jour. Geol. Soc, vi. 47, pi. 10, fig. 2. 1849. 

 Cassidaria laevigata Sowb., Gabb, Tr. Am. Philos. Soc, xv, 1873, p. 222. 



The Santo Domingo form is closely related to S. lintea, a local 

 lateral branch which left no descendants. It differs from S. lintea of 

 the Vicksburg beds only in being free from spiral sculpture in the 

 middle, in the absence of a coronal series of slight pointed tubercles 

 or folds, usually developed in S. lintea, and in attaining a more 

 ponderous growth. The young shells, being striate throughout, are 

 indistinguishable. The Pliocene and Recent S. striata is more coarse- 

 ly sculptured than any laevigata, and does not become so broad. 



The Jamaican S. subloevigata is intermediate between lintea and 

 striata in character, but nearer the latter, of which it may fairly be 

 reckoned a subspecies. 



The genus Sconsia Gray has an interesting history in the 

 American tertiaries, wherein both its origin and development are 

 revealed. The series begins in the Claibornian Eocene with S. 



