134 



CRANIA 



ANOMIA CRANIOLARIS. LimiCBUS. 



Sowerbys Genera, No. \% pi. 4. 



Linnaeus included this in his G. Anomia, from which 

 Bruguiere first separated it, pointing out the distin- 

 guishing characters. The shell is inequivalve, nearly 

 round, and most generally affixed by its lower or inferi- 

 or valve. The three indentations or holes, which are on 

 the internal surface of this valve, appear only to pene- 

 trate it in consequence of the violence necessarily used 

 to detach it from the substance to which it is affix- 

 ed by its external surface. Lamarck therefore does 

 not consider them to be the apertures through which 

 certain muscles protrude, in the manner of the Ano- 

 mia ephippium, but merely depressions or cavities in 

 the lower valve of the shell, while it remains attached 

 and closely adhering to any marine body. These holes 

 or cavities give to the shell the appearance of a death's 

 head or skull in some respects it seems allied to the 

 Terebratulae, while the form of it, and being affixed 

 by the inferior valve, seem to indicate an alliance to 

 the G. Orbicula. But the animal being unknown, the 

 precise genus of it cannot be determined. The writer 



