MADE BY DU. ANTONIO RAIMONDI IN PERU. 289 



sic. It is closely allied to T. sinuata. Park,, bvit differs in having the ribs bent 

 abruptly upwards posteriorly towards the area, and in having them placed closer 

 together on the middle of the shell and more sinuous than in Parkinson's species. 



T. sp. indet. 



There is a small lot of fossils in a bad state of preservation, marked "neighbor- 

 hood of Tingo ; Prov. of Huari ; Dept, of Huaraz ; alt. 3500 metres ; Jurassic V\ 

 Among them is a small Trigonia, recognizable principally by the moulds of the 

 hinge. Not enough of the outline is preserved to ascertain the shape, and the 

 impressions of the surface only suffice to show that it was covered with strong 

 transverse ribs. Fortunately the associated fossils are in a more recognizable 

 state, there being among them Aimnonites Ventanillensis, nob., A. carhonarius, nob., 

 Tellina Peruana, nob., and Crassatella caudata, nob., all of the present paper, and 

 characteristic of the Liassic beds of the coal mine of Pariatambo and the limestones 

 of the Cerro del Ventanillo. The present rock is a black carbonaceous shale very 

 similar to that of the first of the two mentioned localities, but diff"ers in being a 

 little less calcareous, and in the presence of pyrites which lines the cavities left by 

 the decomposition of several of the shells. 

 T., sp. indet. 



A second species, marked as from the immediate neighborhood of Ollon, and 

 probably Cretaceous, is too imperfect for more than a very doubtful identification. 

 From the number of ribs and general form, I believe it to be the T. Tocaimana, 

 Lea, Tr. Amer. Philos, Soc. 1840, p. 256, PI. 9, f. 8, and which may possibly 

 include T. Delafossei, Boyle and Coquand ; Mem. Geol. Soc. France, 2 ser., v. 4, 

 PI. 8, f. 27. This last is represented as differing a little in the costation from 

 Lea's figure ; but that was so imperfect a specimen that the matter must be left 

 an open question until better material shall be available. 



MYOPHORIA, Broun. 

 M. SPIRALIS, n. s., PI. 41, fig. 4, 4a. 



Shell triangular, slightly oblique ; beaks in advance of the middle, spirally 

 incurved in advance of and under the umbones ; anterior end narrowly and regu- 

 larly rounded ; base sloping slightly upwards behind, where it is nearly straight ; 

 most prominent in front; posterior end obliquely truncated; posterior side concave, 

 the concavity bounded by a rounded-angular ridge which runs from the umbone to 

 the posterior-basal angle; surface covered with large, pretty regular lines of growth. 



Figures. Natural size. 



