H. Doc. 129. 17 



TROCHITA, Schum. 



41. T. DIEGOAXA, Con., pi. , fig. 42. Conical ; volutions three, 

 rounded, smooth ; body whorl ventricose. 



Locality. Occurs with the preceding. Miocene? 



CRUCIBULUM, Shum. 



42. c. SPIXOSUM, Con., pi. , fig. 46. Moderately elevated, suhoval, 

 armed with numerous prominent spines in radiating series ; spines 

 smaller, and the series more closely arranged anteriorly ; apex sub- 

 central? prominent, acute ; shell with concentric wrinkles. 



Calyptrcea spinosa ? Soiuerby. 



Locality. San Diego? Recent on the coast of Peru. 



NASSA, Lam. 



43. x. IXTASTRIATA, Con., pi. , fig. 49. Ovate-acute; whorls 5 

 rounded, cancellated ; longitudinal strife nodulous, except towards 

 the base of body whorl ; a deep sulcus behind the beak, two upper 

 volutions entire ; labrum striated within ; spire conical, longer than 

 the aperture. 



Locality. San Pedro. Recent formation. 



The surface of this shell is roughened by a tubercle on the longi- 

 tudinal, at each intersection of the revolving lines. 



44. x. PEDROAXA, Con., pi. , fig. 48. Subfusiform, smooth; vo- 

 lutions rounded, spire conical, longer than the aperture, which is ellip- 

 tical ; columella very regularly concave. 



Locality. Occurs with the preceding. Recent formation. 



This small species resembles Nassa lunata, Say, as the preceding 

 approximate N. trivittata, Say. This is very remarkable, as the two 

 latter are recent shells of the Atlantic coast, associated with each 

 other, both in the sea and in the Miocene deposits of Virginia and 

 Maryland. 



STREPHONA, Broicne. OLIVA, Lam. 



45. s. PEDROAXA, Con., pi. , fig. 51. Small, elliptical; spire 

 conical, about equal in length to the aperture ; base of columella with 

 a prominent fold. 



Locality. Occurs with the preceding. Recent formation. 



A small abundant species, sometimes water- worn, without any pro- 

 minent character, except the fold at the base which is more conspicuous, 

 considering the size of the shell, than is usual in the genus. 



LITTORINA, Ferr. 



46. L. PEDROAXA, Con., pi. , fig. 50. Suboval; spire very short; 

 body whorl abruptly rounded above; aperture obliquely subovate. 



Locality. Occurs with the preceding. Recent formation. 



STRAMONITA, Shum. PURPURA, Lorn. 



47. s. PETROSA, Con., pi. , fig. 47 and 47. Subglobose; whorls 

 4, subangulated ; body whorl with 3 revolving rows of distant tuber- 



