Description of several new Trilobites. 343 



Art. XVIII. — Description of Several New Trilobites ; by 

 Jacob Green, M. D. ' 



Genus Cryphasus — Green. 



Body ovate oblong ; convex ; trilobate ; contractile. 



Buckler with two reticulated, oculiform tubercles. 



Arches of the lateral lobes sustaining a second series of ribs. 



Tail elongated, membranaceous, lobate. 



The generic term which we have applied to this proposed group 

 of animal remains, is derived from the Greek, and is analogous in 

 its signification to that of Calymene, Asaphus, Ogygia, and to some 

 other appellations used by fossil zoologists. The head and the up- 

 per part of the body of these animals resemble those of the Caly- 

 mene of Brongniart. a very slight obliteration of these fossils 

 along the sides and round the tail, would give them all the characters 

 of a Calymene, and perhaps some animals which have been described 

 as belonging to that genus, will be found hereafter to belong to the 

 present group. The genus Cryphseus is also, in some respects, 

 very closely allied to Paradoxides, but as the bucTcler is furnished 

 with tubercular oculiferous prominences, they cannot be confounded 

 together. Professor Brongniart has indeed described, with a 

 mark of doubt, the Paradoxides Laciniatus, as having eyes — oculis 

 marginalibusl but should that interesting relique ever be discovered 

 in a sufficiently perfect state to determine the question, it cannot, 

 we suppose, be included in a genus, one of the principal characters 

 of which is to be blind. Brongniart says of this group, " Les 

 lobes lateraux (of the buckler) sons unis, et ne paraissent point porter 

 d'yeux reels ni meme de protuberances oculiformes." The P. 

 Laciniatus is furnished with a lobate tail, somewhat like that of the 

 Cryphseus, but it differs in many important particulars from any fossil 

 that we have ever observed. Mr. De La Beche does not include 

 it under that name in his list of Trilobites discovered in Europe, 

 though according to Wahlenberg, it is found in Westrogothia. 

 Professor Brongniart, has given, from Mr. Stokes, an imperfect 

 drawing of a trilobite sometimes met with at Dudley in England, 

 (plate 4, fig. 9.) which has some analogy in its form to the animals 

 proposed to be arranged in our new genus, and Count Rasoumou- 

 SKT has figured and described a very remarkable relique, found on 

 the Yaousa, near Moscow, which also has a somewhat similar aspect. 



