25 
TEREBRATULA resupinata. 
TAB. CCCXXV. 
Spec. Char. Transversely ovate, longitudi- 
nally striated ; striae minute, numerous, and 
equal ; imperforate valve most convex. 
Syn. Conch. Anomites resupinatus. Martin 
Pet . Derb . tab . 49. f. 13 and 14. 
Eength about two-thirds the width : the hinge line is 
not very long, but it is straight, and accompanied by 
two nearly flat surfaces, perpendicular to each other, 
between it and the beaks ; that beneath the prominent 
beak of the flatter valve has a triangular foramen in the 
middle of it. The little ridges between the striae are 
often interrupted by punctums that appear to be the 
bases of slender depressed spines : the middle of the 
more convex valve is slightly concave. 
I have met with several hollow specimens of this shell, 
but have seen no vestige of a spiral cartilage in any ; 
nor does it appear that either of the beaks has a circular 
perforation. The form of the hinge strongly resembles 
that of the genus Spirifer, but is not incompatible with 
that of Terebratula, with which at present this species 
must remain. 
Not very rare in the Mountain Limestone of Derby- 
shire. 
