1878.] 39 [Rathbun. 



or less alter the above conclusions. The difference in the character 

 of the materials of the Msecuru fossiliferous beds and the Corniferous 

 is very marked. The former is composed mostly of rather coarse 

 sandstones, the latter of limestones. 



To complete the fauna of the Devonian of Pard there remains the 

 large collection of Lamellibranchs and Trilobites from the Rios Mse- 

 curu and Curud, made by the Geolopjical Commission in 1876. This 

 collection is very extensive and represents a large number of species, 

 which are mostly of North American Devonian types. From a hasty 

 examination of the Lamellibranchs it seems probable that many of 

 the species are identical with New York State forms. Several of the 

 species are of large size, but I am unable to give here the names of 

 the genera represented. Among the Trilobites are species of Homa- 

 lonotus, Phacops and other genera. It is likely that the study of the 

 Trilobites and Lamellibranchs would help to establish more clearly the 

 relations of the Para Devonian to that of N. America. At Erere 

 there were discovered, besides the new Brachiopods, two new species 

 of Lamellibranchs, in addition to those previously described (An- 

 nals of the Lyceum of Natural History of New York, vol. xr, pp. 

 110 to 127, 1875.) They are of very small size and belong to the 

 genera Nucula and Leda. 



Tropidoleptus carinatus and Vitulina pustulosa were discovered by 

 Mr. A. Agassiz in 1875 on the island of Coati, lake Titicaca, Bolivia, 

 demonstrating the probable existence high up in the Andes of about 

 the same Devonian horizon as occurs in Pard. 



