Eathbun.] 244 [December 16, 



belong to tlie above species and increase its already extended range. 

 Exogijm lateralis is found in Europe in the Gres Vert du Mans, 

 Etage supe'rieur, and in the Greensand of Essen on the Ruhr. It also 

 occurs in the Greensand of New Jersey in the United States. Its 

 occurrence in eastern Brazil will give it a distribution not attained 

 bv many of the cretaceous niollusca. 



A comparison of the Pernambuco forms with many specimens of 

 the same species, both from Europe and the United States, gives the 

 following results. The Pernambuco specimens are of the medium 

 size attained by E. lateralis. In outline and general shape they 

 arrree very closely with some of the European and N. American 

 specimens, but the latter vary much among theuiselves. The lower 

 valve is smooth on the exterior. The upper valve is slightly convex, 

 and ornamented by conspicuous, overlapping, concentric layers of 

 growth, which agree perfectly with the s .me features in the"K. Amer- 

 ican and European forms. 



But two specimens wei'e found, both moulds of the shell, showing 

 the exterior and interior, one of both valves, the other of only the 

 upper valve. 



From Sao Jose and Pt. Nova Cruz, Prov. of Pernambuco, Brazil. 



Some little confusion exists as to the synonymy of this species. 

 In 1813 Sowerby described a species of cretaceous oyster as Chama 

 canaliculata. This, with Ostrea lateralis, described and named by 

 Nilsson in 1827, are considered one and the same by D'Orbigny in 

 his Paleontologie Fran9aise, published in 1843, and the name of 

 course changes to Ostrea canaliculata of D'Orb. Still later some 

 writers, I do not know whether by direct observation or not, have 

 given the two as distinct. In the collections to which I have had ac- 

 cess, the specimens, with which I have identified the Brazilian form, 

 have been determined and labeled by good European authorities as 

 Exog'jra lateixdis. I have not seen Exogijra (Chama) canaliculata. 



Family NUCULID^E. 



Nucula Mariae sp. nov. 



Shell minute, slightly elongate, and with the valves moderately con- 

 vex. In the internal mould the outline is obliquely subovate, the beaks 

 are placed far forward, less than one-fourth the length of the shell 

 from the anterior margin, are prominent, elevated slightly above the 



