— 47 — 



This shell does not closely resemble Gabb's species from the older 

 Cretaceous, nor Dr. White's from the same beds. It is more like the 

 living T. sulcata Lamarck, and others. Yet it was found in the Creta- 

 ceous A bed, at the west base of Pt. Loma, by Mr. Fairbanks, together 

 with Ammonites, etc. Two specimens are very perfect. 



Bulla assimilata n. sp. (PI. IV, Fig. 46.) 



Form oval, narrower anteriorly; mouth little longer than spire; 

 outside smooth, shining; lines of growth faint, slight malleations 

 visible with a lens; color pale brown, with irregular fleckings of darker 

 tint scattered throughout. Length, 0.75 inch; breadth, 0.50. 



Very similar to B. adamsi Menke, found living in the same region. 

 That is, however, broader anteriorly, as in other living species. The 

 preservation of color is remarkable for a fossil of such age, and although 

 the specimens are imbedded in very hard stone, the single whole one 

 may be a distorted specimen of Quaternary date, from a raised beach 

 which exists above the Cretaceous in spots. Several living species, 

 with their colors, are found in that bed, which cannot be distinguished 

 from the Cretaceous below in lithological characters, among which 

 were identified Haliotis cracherodi, Leptothyra carpenteri, and others 

 still living. As they do not continue into Div. B, there is no further 

 evidence of their being Cretaceous species. The form of this shell is 

 like that of a young Cyprea, but its coloration is that of a Bidla. 



Tornatina erratica n. sp. (PL II, Fig. 35.) 



Form cylindrical, whorls five, the first immersed, second helicoid, 

 next two rapidly enlarging, and deeply channeled at sutures; fifth 

 diverging suddenly in a loose spiral, the suture advancing | of an inch 

 in one revolution; mouth very long and narrow, lips simple, surface 

 smooth, chalky white. (Anterior end of shell broken off.) Length, 

 0.70 inch; breadth, 0.25. A thin external layer of shell is gone, as 

 shown in the matrix filling mouth, but this was smooth as far as 

 visible. 



Siphonaria capuloides n. sp. (PI. II, Figs. 38, 39.) 



Base broadly oval, dorsally curved backward, beak projecting hori- 

 zontally beyond posterior margin. Anterior surface with eight radiat- 

 ing ribs, from apex to base, and two or three intermediate short ones. 

 Four or five posterior ribs at wider intervals. Extreme apex broken, 

 but was acute, and slightly turned to right, on which side is a sharper 

 rib, probably marking the siphonal groove; but opposite is also an 

 obtuse angle, the two separating the anterior third from the dorsal two- 

 thirds. The strong ribs on this specimen (which is only a cast) indi- 

 cate probably a thin shell, with similar sculpture. It has about the 

 form of Say's figure of the Atlantic S. alternata. Length, 0.65 inch^ 



