17 
for the fauna an horizon earlier than Chemung. The presence of such a 
species as Pugnax pugnus , however, points to an horizon later than Middle 
Devonian. The association with P . pugnus of Cyrtina hamiltonensis, 
Schizophoria striatula, Leiorhynchus mesacostcdis, Palaeoneilo filosa, and 
Leda cf. diversa forms an assemblage comparable with many of those furn- 
ished by the Ithaca fauna of the Lower Portage. It is believed, therefore, 
that the fauna represents an horizon corresponding approximately to 
the Lower Portage horizon of the New York section. 
Observations on Species 
It should not be inferred from the correlation here made and the list 
of species on which it is based, that the Peace Point fossils are without 
the small differences which might be expected to distinguish them from 
a fauna representing so remote a region as central New York. There are 
differences which direct comparison with representatives of the New York 
fauna may yet make it advisable to treat as new species. Pugnax pugnus 
var. is represented by one or two exceptionally well-preserved shells which 
show on the dorsal valve very fine radiating striae, 5 or 6 to 1 mm., and 
very fine concentric stride on the ventral valve. These are not recorded in 
the descriptions of P. pugnus from Iowa or New York, and appear to 
represent a northern geographic variation of the Iowa and New York 
shells. 
Cyrtina billingsi var. symmetrica n. var. 
A well-marked variety of C. billingsi, represented by three or more 
specimens, is distinguished by a nearly or quite symmetrical ventral valve 
the beak showing practically no deflexion to the right or left. The sinus 
and fold are rather less well defined than in Cyrtina billingsi. 
Types. Nos. 5593, National Museum of Canada. 
Cyrtina hamiltonensis var. 
A single small specimen with a highly granulose surface marked by 
about 12 plications on each valve is here considered a variety of C. 
hamiltonensis. Additional material showing the same peculiarities, if found 
in the future, may justify treating this form as a new species. 
Spirifer tullia var. Whiteaves 
The three specimens studied appear to be intermediate between S. 
iullia and the variety figured by Whiteaves, having fewer plications than 
the former and more than the latter, but apparently closer to Whiteaves’ 
variety than Hall’s species. 
Many of the shells of Schizophoria striatula are perforated by the trails 
of a boring organism, probably a sponge, which are generally about | 
mm. in diameter. These in some cases penetrate the shell at a sharp 
angle, but more frequently trench the surface in zigzag courses. Shells 
which are conspicuously marked with these borings are commonly much 
wave and water-worn, having escaped covering by sediments for a suffi- 
ciently long period to provide opportunity for these parasitic organisms 
