276 
PALAEONTOLOGY OP NEW-YORK. 
Trematospira multistriata. 
12 3 
Figs. 1 &. 2. Ventral and front views. 
Fig. 3. The interior of a ventral valve filled with stony matter, and ground so as to show the spires 
6 
Fig. 4. Trematospira perforata. The upper part of the shell enlarged, showing beak of ventral 
valve, perforation and triangular space below. 
Figs. 5 & 6. Trematospira costata. Dorsal and front .views of a specimen. 
Genus Riiynchospira (Hall). 
In the third volume of the Palaeontology of New-York (page 213), I 
suggested this name as a subgenus of Trematospira ; but subsequently, 
from certain peculiarities of hinge-structure, general form, etc., I was 
induced to propose it as a distinct genus. Although approaching the 
typical species of Retzia, I am not satisfied of the identity of the two; 
and until we have better information regarding the latter genus, I pro¬ 
pose to place under Rhynchospira those forms which are similar to R. 
formosa of the Lower Helderburg group.* 
Rhynchospira lepida. 
PLATE XLV. 
Rhynchospira lepida : Hall, Thirteenth Report on the State Cabinet, p. 83. 1860. 
Shell small, broadly suboval, with the valves subequally convex, and 
the beak of the ventral valve extended. 
*In the Sixteenth Report upon the State Cabinet of Natural History, pp, 53-59, I have discussed 
the relations of Retzia, Trematospira, Rhynchospira, with the materials at that time accessible 
to me. 
