CAMAROPHORIA 171 1 



ellas which are produced anteriorly more than one-third the length of the 

 valve as a spondylium-like platform which rests upon the floor of the 

 valve, not being raised on a median septum. 



Brachial valve more convex than the pedicle, the greatest convexity 

 near the middle, the surface curving downward in all directions from the 

 point of greatest convexity but more gently to the anterior margin than 

 in other directions ; mesial fold obsolete in the posterior half of the valve, 

 only moderately elevated in front, rounded transversely and sometimes 

 scarcely differentiated from the lateral slopes; the beak broad, strongly 

 incurved beneath that of the opposite valve ; the plications similar in form 

 and number to those of the opposite valve. Internally no cardinal pro- 

 cess is present, the hinge-plate is broad and not divided and is produced 

 anteriorly in a pair of crura, at the apex of the beak it is supported by a 

 median septum from each side of which, at a position about midway be- 

 tween the hinge-plate and the floor of the valve, springs a lateral process 

 which curves slightly away from the floor of the valve, anteriorly the 

 hinge-plate becomes entirely unsupported by the median septum before 

 the articulation of the hinge is past, but the median septum itself with 

 its transverse processes which develop into a broadly V-shaped platform 

 extends for one-third or more of the length of the valve, the platform 

 gradually rising higher above the floor of the valve and terminating ab- 

 ruptly with the septum in front, posteriorly the median septum continues 

 for a short distance towards the front as a gradually decreasing longitud- 

 inal ridge in the bottom of the V-shaped platform. 



The surface of both valves, in addition to the plications, is marked by 

 more or less obscure lines of growth. 



Remarks. In its external aspects this little shell resembles, to some 

 extent, some of the Devonian species of Pentamcrella, but its internal 

 characters are not essentially different from' those of Camarophoria, in 

 which genus the species is placed without any hesitation. The spondy- 

 lium-like platform of the pedicle valve resting upon the floor of the valve, 

 is similar to the condition in Camarophorella, and the median septum of 

 the brachial valve with its transverse processes is also similar to that 

 genus, but it lacks the lateral septa which in that genus connect the outer 

 margins of the V-shaped platform with the floor of the valve. Camaro- 

 phorella has been shown recently to be a spire bearing shell, 1 but there is 

 no evidence in the specimens of the species here described that this form 

 possessed any brachidium beyond the crura, although if such had been 

 present it would have been destroyed in the separated valves which alone 

 have been available for the examination of the internal parts. Externally, 

 the shell is distinctly unlike Camarophorella in having distinct longitudinal 

 plications. 



iHyde, Proc. Boston Soc. Nat. Hist., vol. 34, No. 3, pp. 35-65 (1908). 



