FROM PLIOCENE CLAY BEDS IN COSTA RICA. 359 



ARCHITECTONICA, Bolt. 

 A. BISULCATA, d'Oib., sp. 



Solarium, id., d'Orb., La Sagra, p. 66, PI. 18, figs. 17-20. 



A single, but very well preserved specimen. Found living on the Cuban coast. 



A. GRANULATA, Lam., A. S. v., V. 1, 3, 



S. quadriseriatum, Sby., Q. J. G. S., v. 6, p. 51, PL 10, fig. 8. 



Further comparisons of large suites of both recent and fossil specimens, in- 

 cluding some from Costa Rica, convince me of the identity of the fossil and recent 

 shells. 



CONUS, Linn. 



C. LEONiNUS, Hwass, Encyc. Metb., v. 1, Part 2, p. 683, PL 334, figs, 5-6. 



Half a dozen specimens, all retaining their color pattern. A well known West 

 Indian shell. 



C. coNSOBRiNus, Sby., Q. J. G. S,, v. 6, p. 45. 



C. granozonatus, Guppy, loc. cit., v. 22, p. 287, PL 16, fig. 5. 



Two or three of the specimens retain traces of coloration ; the pattern resem- 

 bling that of C. Haitensis, a dark ground, irregularly streaked and flaked with 

 white, the light color being arranged more or less spirally. I am in some doubt 

 as to whether this is really the remains of the color of the live shell, or whether 

 it may not be connected with some peculiar condition of fossilization. 



The species is found fossil in Jamaica and Santo Domingo. It is not known 

 living. 



C. REGULARis, Sby. (Conch. IlL), PL 46, figs. 45-48." 



An abundant fossil of Costa Rica which agrees with the descriptions and figures 

 as well as with recent specimens from the Gulf of Nicoya, except that the surface 

 is described as smooth. I find, however, that some of the recent shells are 

 grooved and even marked by moniliform ribs, especially on the anterior end. The 

 fossils vary from more nearly smooth than some of the recent specimens, to a form 

 covered over the entire surface with large ribs, with equal, deep interspaces. C. 

 marginatus, Sby. (fossil in Santo Domingo), seems to be only an older form of the 

 same species. It is smaller and more robust than the recent shell, though ap- 

 proached in this respect by some of the Costa Rican fossils. Its surface is regu- 

 larly marked by square revolving ribs, with equal squarely sunken interspaces, 

 and even this character is approached by some of the specimens before us. 



