S58 
PALAEONTOLOGY OF NEW-YORK. 
SfJBGENUS AMBOC(ELIA. 
In the Thirteenth Report on the State Cabinet*, I proposed the name 
Amboccelia as a generic designation for several species of fossils, of which 
Orthis umbonata of Conrad was regarded as the typical form. This fossil 
bears much resemblance to Spirifer urii, Fleming = S. unguicidus , Phil¬ 
lips ; but I do not regard the identity of the two as demonstrated at the 
present time. The European species has been placed by King and M‘Coy 
under the Genus Martinia of the latter; the typical species of which, 
mentioned by M‘Coy its author, are Spirifer a decora, S. elliptica and S. 
glabraf. These European species are not more nearly related to Orthis 
umbonata than are some of our own species, in which we observe the 
ordinary characters of the Genus Spirifera. 
But there are a few points* of distinction between these and the form 
I have proposed to designate Amboccelia. Whether these are of generic 
importance, may remain a question ; but they differ from those on which 
the Genus Martinia was founded, and the allied species Spirifera urii = 
S. unguiculus was only included under the genus at a later period^:; so 
that if that one be proved generically distinct from Spirifera, it could 
not supersede the type of the genus indicated by M‘Coy. 
In the ventral valve, the thickened margins of the fissure are produced 
in short strong teeth; but there is scarcely any extension of the dental 
plates into the cavity, or below the inner margin of the fissure. 
In the dorsal valve, the bases of the crura continue attached to the 
inner surface of the valve for more than one-third of its length, before 
becoming free. There is a lateral projection from these crural bases, 
* Thirteenth Annual Report on the State Cabinet of Natural History, pp. 71 & 72. I860, 
t Synopsis of the Carboniferous Fossils of Ireland, p. 139(1844). Mr. Davidson, in his Monograph 
of British Carboniferous Brachiopoda, places S. decora as a variety of 5. glabra, and S', elliptica as a 
variety of S. lineata; while Martinia oblata, M. obtusa and M. symmetrica are regarded as simply 
tarieties of Spirifera glabra, and Martinia mesoloba and M. stringocephala as varieties of S. lineata. 
X British Palaeozoic Fossils, p. 377. 1855. 
