216 ANNUAL EECORD OF SCIENCE AND INDUSTRY. 



The first discovery mentioned by the professor was that of 

 a living Pecten, very similar in general appearance to a fossil 

 form known as P. paradoxus, found in Germany, and which 

 he had been inclined to consider a distinct genus, on account 

 of certain peculiarities which are not shared by any living 

 shells known up to this discovery. The specimen found is, 

 however, strictly referable to the same genus as the paradox- 

 us, especially as it has the same prominent radiating ribs 

 arising on the inner surface of the shell valve, to which the 

 fossil is indebted for its specific name. Although of very 

 small dimensions, being scarcely two thirds of an inch in di- 

 ameter, it is yet a specimen of very great significance. 



The second discovery was that of a very remarkable crus- 

 tacean, and is, in part, the realization of the expectation of 

 finding "genera reminding us of some amphipods, and iso- 

 pods aping still more closely the trilobites than Serolis." A 

 specimen answering fully to this statement was taken in for- 

 ty-five fathoms, and at first sight seemed like an ordinary 

 isopod, with a broad, short, flat body. This, however, is not 

 referable to any of the orders or families of Milne-Edwards 

 or Dana, and, for reasons adduced, it has very striking rela- 

 tions to the trilobites, and is, indeed, like them, one of those 

 types combining the structural features of several independ- 

 ent groups. It resembles the trilobites in the fact that the 

 head is distinct from the thoracic regions ; and the large fa- 

 ceted eyes and the facial suture across the cheeks connect it 

 so closely that but for the presence of antenna?, which project 

 from the lower side of the anterior margin of the buckler, the 

 resemblance would amount to an absolute identity in struc- 

 ture with the trilobites. The character of the mouth is also 

 that of the trilobite, while the antenna? cause its reference to 

 the isopod. For this new genus the name of Tomocaris 

 peircei is proposed. Letter to Prof. Peirce. 



SMITH OX TOMOCAEIS TEIECEI. 



Professor Smith, of Yale College, in discussing the an- 

 nouncement by Professor Agassiz of a remarkable new crus- 

 tacean (Tomocaris peircei) discovered off the coast of Brazil, 

 states that, from the description, it is evidently congeneric, 

 if not identical with the Brongniartia trilobites of Dr. James 

 Eights, described many years ago, and since referred to the 

 genus Scrolls. 4 J), May, 1872, 373. 



