NE.ERA. 47 



Loven as Embla Korenii, Deshayes as Corbula vitrea^ 

 and Tiberi as Cumingia parthenopoea. 



Genus II. NE.^R^A*, (NEARA) Gray. PL II. f. 4. 



Body globular, thin : tubes unequal in size, clothed with a 

 few long filaments : foot lanceolate. 



Shell fig- shaped, inequilateral, thin ; posterior end twisted 

 and extended into a beak-like process : epidermis membranous : 

 teeth, sometimes a small cardinal in each yalve, or a crest-Hke 

 laminar lateral on the posterior side of one valve or both ; 

 certain species have also a free calcareous ossicle. 



The late Capt. Brown first suggested the generic 

 separation of the present group of shells^ which are 

 distinguished no less by the singularity than by the 

 elegance of their shape. His services in the cause of 

 British conchology would have been greater if his 

 attention had not been distracted by so many other 

 branches of zoology. Good results, however, were pro- 

 duced by his publications, especially in promoting the 

 faculty of observation in young persons. Clark repu- 

 diates the genus, and merges it in Anatina, on the 

 ground that each has an ossicle. This leads to the 

 consideration of the difficult question, what is a genus ? 

 Nor can I agree with him that we have but one species 

 of Neaera. Perhaps in a few centuries hence, or sooner, 

 his opinion on the last point may be found correct ; or 

 possibly the very notion of species may be classed among 

 the vulgar errors of a half- enlightened age. What our 

 Poet-laureate says is true, that 



" Science moves, but slowly slowly, 

 Creeping on from point to point:" 



or as Seneca puts it, " Multa hoc primum cognovimus 



* A Sea-Nymph mentioned by Spenser. 



