376 DESCEIPTIONS OF NEW SPECIES OF FOSSILS 



MYSIA, Leach. 



M. ORBELLA, Gld. Sp. 



Lucina (Diplodonta) orbella, Gld. Otia, p. 212. 



Described from San Diego. I cannot find a single point of difference between 

 my fossils and authentic specimens of Dr. Gould's species in the Museum of the 

 Academy of Natural Sciences of Philadelphia. 



ASTARTE, Sbj. 

 A. MERimoNALis, Gabb, n. s., PI. 4t, fig. T8. 



Shell minute, robust, triangular, oblique ; beaks placed well in advance and 

 prominent ; posterior cardinal margin sloping rapidly downwards and backwards, 

 nearly straight, curving into the posterior end, which is narrow, truncated, and 

 slopes outwards a very little. Anterior end sloping much more abruptly than the 

 posterior, and slightly concave. The most prominent part of the anterior end is 

 near the base. Base in front of the sharp posterior angle very slightly concave, 

 and bending downwards becoming broadly convex in the middle and in front. 

 Surface marked by a few large concentric ribs becoming smaller on the upper part 

 of the shell. 



Length 3 mm. 



Very rare near Limon, Costa Rica. 



GOULDIA, C. B. Ad. 

 G. GUADALUPENSIS, d'Orb. sp. 

 Crassatella Ouadalupensis, d'Orb., La Sagra, p. 289, PI. 2Y, f. 24-26. 



Mr. G-uppy is certainly wrong (Quart. Journ. Geol. Soc, 1876, p. 530) in 

 including this with Martinicensis. The error is so great that I may be almost per- 

 mitted to think that he has not seen the present species. I infer so from the fact 

 that I did not find it, but the other species only, fossil in Santo Domingo, and now 

 I find this alone, and very abundant in Costa Rica. G. Martinicensis is a regular 

 equilateral shell, while among over sixty specimens now before me of the present 

 species, not one is perfectly equilateral and some are very oblique, not only in the 

 adult, but even in the very young stage. 



As to the change of generic name from Gouldia to Crassinella, I beMeve all lead- 

 ing authorities have declared against the principle. To go thrpugh natural history 

 names and give new ones wherever a name is repeated w^ould create a terrible 

 revolution in nomenclature, and could accomplish no good whatever. No con- 

 fusion exists. Nobody could mistake Gouldia the shell for Gouldia the bird, and 

 what cannot be done on a grand scale certainly cannot be done in individual cases. 



