TRIASSIC ROCKS. 
o' w- 
00 
stria). The coarse ribbed species in- his work are not flatten¬ 
ed, or bilobed. The bilobed species, on the other hand, are 
fine-ribbed. C. llardrensis , a shell of the same size, but 
without a furrow, comes nearest our fossil. It is the common 
British species. 
Locality .—Niti Pass. 
2. AVICULOPECTEN HYEMALIS-2V Sp. 
Plate 5, fig 1 . 14. 
A. semiuncialis. Vulva profundior convexa, subtrigona, apice acuto, anvil ms 
modicia abrupte depressis. Superficies costis 16 eminentibus, equidistantibus, 
intcrlineatis. 
The left valve of this small species—only half an inch long 
and as much wide—is orbicular, regularly convex, sub-trian¬ 
gular, and rounded in front. The beak is sharp, and project¬ 
ing ; the cars unequal—the anterior one small with a few 
striae ; the posterior broad, notched and pointed, and both 
abruptly sunk. The surface of the shell is regularly radiated 
by about sixteen strong sharp ribs, equally distant from each 
other, and interlined regularly by a finer one between each 
pair. 
The ribs are nearly smooth, a little nodular here and there, 
and crossed by concentric ridges of growth. 
It is distinguished from the Aviculopeclen cequaUs (iYPCoy), 
a species described by him in his f Carboniferous fossils of 
Ireland/ by the nearly smooth and equal ribs, and the regu¬ 
lar! p-convex shell. It is also a much larger species. 
Locality .—Niti Pass. 
TBIASSIC. 
The portion of Colonel Stracliey^s collection which has excited 
most interest in England is undoubtedly the small but charac- 
