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Guppy Reprint 



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artistic skill for the execution of such work is not to be found 

 here. The figures are only intended to give, in conjunction 

 with the descriptions, a fair general idea of the shells wished 

 to be represented, and it should not be supposed that they 

 are meant for finished drawings. 



§ 2. The Species of Nucula and Leda. 

 1. Nucula schomburgki. Forbes (PI. vii., f. 10.) 



N. schomburgki, Forbes, in Schomburgk, History of 

 Barbados, p. 565. 



N. schomburgki Guppy, Geol. Mag., 1867, p. 500. 



The likeness of this shell to N. bivirgata, N. ornatissima, 

 and N. cobboldice was remarked by Prof. Forbes when 

 describing it, and he gave the greater weight to its alliance 

 with the latter. Nevertheless, to me it appears more nearly 

 allied toA^. bivirgata. The recent species of the small group 

 of divaricately ornamented Nuculas, in which the above 

 extinct species find their place, are N. castrensis and N. 

 divaricata. Eocene, Barbados, Trinidad (Sanfernando). 



2. Nucula crosby ana n. sp. (PL vii, f. 3, 3a). 



Oval-elliptical, sub-equilateral, scarcely attenuated behind, 

 thin, smooth, shining, indistinctly marked by some close 

 concentric riblets, more visible towards the regularly curved 

 ventral margin ; ends rounded, slightly gaping, the anterior 

 end the shortest, forming an angle with the hinge-line ; 

 umbones small, scarcely prominent; hinge-teeth about twelve 

 before the ligamental pit and about fifteen behind it. Length, 

 16 mm. ; height, 8^ mill. 



I received from Mr. W. O. Crosby two dead valves of this 

 species, dredged by him in the Gulf of Paria. In shape it is 



