464 PROCEEDINGS OF THE ACADEMY OF 



This is a large species, and perfect specimens, probably, some- 

 times measure three inches in length ; one extreme specimen is 

 strongl}^ suggestive of Tarritella^ and others resemble the living 

 Opalia borealis, Gould, common at different places along the 

 coast. It forms a carious, but complete link between the forms 

 like S. gronlandica, and the typical Ojjaliae. 



Locality, about eight miles north of San Diego, Caliibrnia, 

 associated with Pecten and Vola. 



Museum of the Smithsonian Institution. 

 Opalia anomala, Stearns. Plate 27, Fig. 1. 



Shell solid, imperforate, elongated-conical, spire gradually 

 tapering; whorls convex, when perfect probably 11 to 14 in 

 number, nearly smooth, being marked only by incremental, 

 and, occasional!}', in some specimens, by an outgrown varix ; 

 suture well defined ; basal whorl traversed transversely by an 

 inconspicuous rib, varying in prominence, in some specimens 

 barely discernible ; the convexity or angularity of the lower part 

 of the basal whorl modified by the presence or absence of the 

 basal rib. 



Number of specimens 10. Average length 2 inches. 



Longitude of smallest . . . .1.87 inches 

 " of largest 2.37 " 



As the apex whorls in all of the specimens are wanting, a care- 

 ful estimate would add .25 inch to the foregoing average, making 

 tlie latter 2.25 inches in perfect shells. 



This species is readily recognized by the absence of longitudinal 

 ribs, though one or two specimens indicate faint plications near 

 the apex. 



Locality, the same as the preceding species. 



Collected by Mr. Henry Hemphill, of Oakla::;'.' 



Museum of the Smithsonian Institution 



/ t 



