242 Mr, Gray on the Synonima of the [Oct. 



species in his genus which recent observation has proved not to 

 agree with the characters that he has given to it. Thus A, 

 cramolaris has a similar animal, but has no teeth in its hinge, 

 and has consequently been formed into a genus, under the name 

 of Craniay by Bruguiere. A, spinay of which the animal is 

 unknown, has been equally separated into a genus called Flu- 

 giostama, by Lamarck. The animal again of A, Ephiphium, A. 

 Cepa, A.EiectricUf A.squamu/a, and A. patelliformis, is very dis- 

 similar from that described by Linnaeus as appertaining to 

 Anomia. It is in fact most nearly allied to that of the oyster, 

 and is, therefore, what Linnaeus calls an Ascidia. To these lat- 

 terspecies, Bruguiere has retained the name of ^wo/wm, which is 

 much to be regretted, as had he studied the beautiful character 

 of Linnaeus, he would have found that that author did not intend 

 these species as the type of his genus ; and there is little doubt 

 that had he known their animal, he would have placed them with 

 the Ostrecdj or have formed a new genus for their reception ; 

 there being no part of his system where he so rapidly increased 

 the number of his genera as in the Testacea, It is more to be 

 regretted that later conchologists should not have corrected this 

 error, but have let it continue so long, that although it errs 

 against one of the best laws of nomenclature, we are almost 

 inclined to allow it to remain without correction, for Bruguiere's 

 iiames have been in general use both by conchologists and 

 geologists, and consequently any alteration in them would 

 introduce much confusion into these delightful sciences. Still, 

 however, it is but proper to point out that the immortal Swede 

 was the first to describe with accuracy the curious animal of the 

 Brachiopodous Mollusca. 



But I do not consider that the same line of conduct should be 

 pursued in the next case which I am going to state, where even 

 greater confusion has been caused by the haste to form conclu- 

 sions, and by little attention being paid to the characters given 

 by the original describers of genera. 



Linnaeus, in his " Fauna Suecica/* has placed as the first 

 species of Aftomia, a shell, under the name of A. craniolaris ; 

 and here I may object to the opinion held by many persons, 

 that the first species of the genus is to be considered the type of 

 it. This may be the case in the works of Fabricius, but I 

 beUeve not so in those of most other authors. Linnaeus appears to 

 have referred this shell to the present genus, from it having 

 sometimes, as he describes, three holes in its lower valve ; but 

 these holes are only the places where the adductor muscles of 

 the animal have been attached, which, being of a more brittle 

 texture, decay sooner than the rest of the shell, which is always 

 found in a fossil state. Bruguiere has formed this shell into a 

 genus under the name of Crania, from the similarity of the three 

 scars, or holes, to the apertures in a human skull that correspond 



