374 
PALAEONTOLOGY OF NEW-YORK. 
nent umbo. The hinge-plate is extended in gradually converging vertical lamellae which 
are joined to the shell throughout their length, while the crura are extended into the 
cavity in thin free lamellae. Genus Anastropria,* of which Pentamerus verneuilii, 
P. interplicata and P. reversus are types. 
7. Forms elongate, not lobed. Yentral valve with connected dental lamellae, forming a 
trough supported on a septum. Dorsal valve with free crura : no area. Shell-structure 
punctate. Genus Amphigenia : Type Pentamerus elongatus ( Vanuxem ) = A. 
elongata. 
These modifications of a type, of which, until recently, but two genera have 
been recognized, are well marked in nature, and they seem to me to demand some 
farther recognition than that of subordination to the Family Rhynchonellid.®. I 
shall therefore propose the Family Pentameridve to include the genera above 
enumerated, as well as the Genus Camarophoria, and probably Triplesia and 
some of the species of Camarella,! and perhaps also the Genus Gypidia of Dal- 
majt, making G. conchydium the type.! In this arrangement, it appears to me that 
we have a well-marked family of Brachiopoda which has existed from the earliest 
palaeozoic^epoch, and has continued throughout the entire series to its close. 
* I am aware that Mr. Shaler, of the Museum of Comparative Zoology at Cambridge, in a Bulle¬ 
tin of that Institution, has proposed the name Brachymerus for these forms ; hut since that name is 
preoccupied for a genus of Coleoptera, it cannot be adopted in this relation; and my own determi¬ 
nation of the generic distinction of these forms having been made long since, I shall adopt the name 
proposed above. 
t I cannot recognize the rhynchonelloid typical species of Camarella as congeneric with many of 
those more recently placed under that genus by its author. 
J In the revision of the Pentameridve, I am by no means sure that the Genus Gypidia will not he 
recognized. I have under consideration at the present time an American species of similar external 
character, presenting certain modifications of the hinge-plate in the dorsal valve, which will require a 
distinct designation. 
