On Trichites, a fossil genus of Bivalve Mollusks. 43 



counsel by words without knowledge," Job. xxxviii. 2; he also 

 records fragments in his collection from Risington and Birdlip 

 Hill in Gloucestershire. The generic name was of course de- 

 rived from its capillary or hair-like structure. Far from joining 

 in the foregoing censure, we are rather disposed to respect the 

 discrimination which recognized this obscure generic form in the 

 earliest infancy of conchology. It was observed by Saussure in 

 the Coralline Oolite of Mount Saleve near Geneva, and described 

 by Deluc in the first volume of the great work of Saussure on 

 the Alps, p. 192, and figured in part 2. fig. 5, 6. This eminent 

 naturalist ascertained some of the general features of the genus ; 

 the great thickness of the test, its fibrous structure, analogous, he 

 observed, to that of Pinna, and its inequivalve form ; this latter 

 character, he observed, compelled a generic separation, and he 

 proposed to call it Pinnegene. Deluc seems to have been unac- 

 quainted with the prior claim of Lhwyd. Guettard and De- 

 france observed it in the oolitic rocks of Normandy ; they re- 

 garded it as a distinct genus, but do not appear to have con- 

 tributed anything material to its elucidation. The latter author's 

 views are contained in an article contributed by him to the 'Dic- 

 tionnaire des Sciences Naturelles/ torn. lv. 1828. 



Deshayes, in his last edition of Lamarck's Conchology, does 

 not recognize its generic value, but describes Deluc's species 

 (torn. vii. p. 68) under the designation Pinna Saussurei ; the 

 materials at his disposal seem to have been very imperfect, and 

 in consequence his description is incomplete and calculated to 

 give an erroneous idea of its characteristic features. The term 

 * subsequivalvis ' for instance does not accord with Deluc's figures ; 

 it is stated to gape posteriorly, which, judging from our speci- 

 mens, must be an error ; the character of the terminal extremity 

 and interior of the hinge-line are not mentioned. The only other 

 recent notice of the genus which we have discovered is contained 

 in the volume of Dr. Pictet, which is devoted to fossil concho- 

 logy, where the figures of Deluc are copied on a reduced scale, 

 but no additional information is given. From the absence of all 

 notice of the genus by the leading systematic writers on concho- 

 logy, it may be concluded that they did not recognize the di- 

 stinction of Deluc's shell from Pinna, or having no personal 

 knowledge of the form, they hesitated to allow it a place with 

 •lizitl irenera. It has therefore hitherto existed almost on 

 the horizon of science as an obscure and problematical object, 

 which it will be our present endeavour to bring more nearly 

 within the grmtp <>t' the conchologist. 



Generic Character. 



Shell of fibrous structure, thick, ovate, obkmg, inequivalve, ine- 

 quilateral and irregular : nmbones terminal, produced and 



