220 
PALAEONTOLOGY OF NEW-YORK. 
elevated septum running to the base of the shell. Muscular imprints 
0 
confined to a narrow oval space. 
Surface apparently smooth : shell structure punctate, and, when perfect, 
covered with minute hair-like spines. 
The larger species of this genus present some analogy in external appearance with 
Spirigera , and the presence of internal spires increases the similarity. The cardinal 
teeth resemble those of Spirigera and Merista : the punctate shell and the structure 
of the hinge are, however, quite different. In form, and in the punctate character, 
it simulates Magas; while the elongate cardinal process of the dorsal valve resembles 
that organ in Thecidium. The genus, however, when regarded in all its features, is 
very distinct from any of these; and the species will constitute, so far as regards 
American palaeozoic brachiopoda at present known, a well-marked, beautiful, and 
interesting little group. The geological range at present known extends from the 
Niagara, through the Lower Helderberg, to the Hamilton; though it is probable we 
shall find them in other strata. 
Kucleospira ventricosa ( n. s.). 
Plate XIY. Fig. 1; and Plate XXYIII B. Fig. 2-9. 
Shell globose : valves almost equally convex. Ventral valve having a 
narrow sinus extending down the centre from beak to base : beak 
projecting above the other, strongly incurved and pointed (in many 
specimens the beaks are nearly equal). Dorsal valve having a central 
depressed line, which is less conspicuous than in the opposite valve : 
false area very small, concave. 
Surface marked by concentric lines of growth; and, when perfect, 
covered with minute hair-like spines, which, when removed, leave a 
punctate surface. 
The interior of the dorsal valve shows a faintly defined muscular area, a longitu¬ 
dinal septum, and prominent recurved cardinal process, with an accessory process 
on each side for the attachment of the spires. The ventral valve shows a longitudinal 
septum similar to that of the opposite valve, with a more or less strongly defined 
muscular depression; area, or false area, a concave triangular space, over which the 
acute beak is arched. In well-preserved specimens, the beak appears to be minutely 
