SECTIOlNr I. 



BRACHIOPODA FROM THE SEVER AI. MARL BEDS OF THE STATE. 



DESCRIPTION OF SPECIES. 



The fossil Brachiopoda are not very well represented in the Cretaceous 

 formations of America, and the New Jersey beds form no exception to this 

 rule. In Europe, as a general thing, this class of sliells is quite abundant, 

 and although the genera are not as numerous as they are in Paleozoic 

 formations, yet the species are many. But in America there are few^ spe- 

 cies, and those mostly confined to four genera, namely, Terebratida^ Ter- 

 ebratulina, Terebratella^ and Bliynchonella. In New Jersey, so far as at 

 present known, only three of these genera are represented ; the last one, 

 Bhynchonella, being entirely absent. In regard to individuals, two of the 

 species known to occur within the State may be said to be abundant, Tere- 

 bratula Harlani and TerebrateUa plicata. The latter is moderately abundant 

 as scattered individuals in the Gryphaea beds of the lower marls, but has 

 never yet been found in large quantities; while the former, T, Harlani, oc- 

 curs in vast numbers, forming, at several locahties, beds of several feet in 

 thickness, made up almost entirely of the broken and often w^ater-w^orn 

 valves of this species, with a very moderate number of entire individuals 

 The conditions of life prevailing in the New Jersey seas during the forma- 

 tion of the green marls do not appear to have been favorable to the exist- 

 ence of this form of Molluscoid, but in a few localities the vast abundance 

 of Gryphcea vesicularis which had accumulated just below, and whose shells 

 had formed beds of several feet in thickness, appear to have furnished, 

 by their maceration and solution, a sufficient amount of calcareous material 

 to have afforded the proper conditions requisite for these shells, and for 

 vast numbers of foraminiferous bodies as well ; as the so-called calcareous 



