* BIVALVIA. 35 



there are other species which are nearly unknown to science; these circumstances, it is 

 trusted, will sufficiently incite the industry of local collectors, and that ere long our knowledge 

 of this obscure form will be augmented. On referring to the earliest notice of Trichites, we 

 find that it dates even to the period when fossil shells were regarded as mere sports of 

 nature, as the product of a supposed plastic power possessed by inorganic matter. Dr. Plot, 

 in his 'Natural History of Oxfordshire, 1676,' apphed the term Trichites to fragments of 

 these shells, and figured a specimen in pi. 7, fig. 7 ; these he regarded merely as mineral 

 curiosities. To Lhwyd is due the merit of having discovered their true position in the 

 animal kingdom, and their distinctness from all known shells of Mollusca. He described 

 in his ' Lithophylacii Britannici,' several species from the Coralline Oolite of Oxfordshire, 

 a fact the more remarkable, when it is remembered that more than a century afterwards 

 the majority of systematic writers omitted the genus altogether from their works, or 

 confessed their imperfect acquaintance with it. In Woodward's ' Catalogue of British 

 Fossils, 1723,' it seems to have been confounded with the Catilli of the cretaceous rocks, 

 and is placed with the " Testae incerti generis." Guettard recognised it in the Oolite 

 rocks of Normandy, and mentioned it under the name of Trichites. 



Deluc, in the great work of Saussure, ' Voyages dans les Alpes,' i, p. 192, made it a new 

 genus, under the name of Pinnigene, and figured a species which has not been recognised 

 in this country; he does not seem to have been aware of the identity of Pinnigene with the 

 Trichites of Lhwyd. The article Trichites, in the ' Dictionnaire des Sciences Naturelles,' 

 tom. Iv, contributed by Defrance, contains a digest of all the information which had been 

 acquired respecting this obscure form. Deshayes, in the 2d edition of Lamarck, ' Anim. s. 

 Vert.,' tom. vii, p. 68, refers Deluc's species to Pinna, under the name of Pinna Saussurei, 

 but states however that he had never seen a perfect specimen. Pusch, in his ' Polens 

 Paleontologie, 1835,' page 45, ofiers some remarks upon fragments which he had detached 

 from the rocks of the middle Oolite at Brzegi and Koritrice, but having no knowledge of 

 the entire form, he refers the fragments to Catillus. Pictet, in his ' Traite Elementaire de 

 Paleontologie,' allows the generic value of Trichites, and reproduces the figures of Deluc 

 reduced in size. Lastly, the reader is referred to a notice of this genus in the ' Annals 

 and Magazine of Natural History for 1850,' p. 347, by one of the authors of this 

 monograph. 



Trichites nodosus, Lycett. Tab. Ill, fig. 11. 



Trichites nodosus, Lycett. Ann. and Mag. of Nat. Hist., 1850, p. 347, t. 10. 

 — — Bronn. Leth. Geog., p. 221, t. 20, f. 1, 1851. 



Testa subquadratd, convexd, valvis valde incequalibus, valvd sinistra convexd, valvd 

 dextrd concavd ; valvis varicibiis subradiantibus irregularibus interdmn dichotomis. Valvd 

 minora nodis nonnullis irregularibus. Apices valvarum attenuata et obliquce. 



Shell subquadrate, convex, the valves very unequal, the left valve being very convex or 



