REVISION pP SPECIES REFERRED TO GENUS BATHYURUS 
61 
Hystricurus crotalifrqns, (Dwight). 
Batkyurus ? crotalifrons, Dwight, 1884. American Journal of 
Science, 3d series, p. 253, PL 7, figs, 4, 4a, 5, 6. 
Differs from H. conicus only in the longer and more tapering 
glabella. Found in the Beekmantown at Rockdale, New York. 
Hystricurus cordai, (Billings). 
Batkyurus cordai , Billings, 1860, Canadian Naturalist and 
Geologist, Yol. Y, p, 321, fig. 26. 
Batkyurus seelyi , Whitfield, 1889. Bulletin American Museum 
Natural History, Yol. 11, p. 62, PL 13, figs. 8-14. Not 
B. seelyi, Whitfield, Vol. I, 1886, which* is Bolbocepkalus 
seelyi. 
This species has a smooth, and not a pustulose surface. It 
has been found in the conglomerates at Point Levis, and in the 
Beekmantown at Philipsburg, Quebec, Beekmantown, New 
York, and probably at Comstock Landing, New York. Also 
at Cow head, Newfoundland. (Specimens identified by Billings 
as B. conicus ). 
Family Proetib^: Barranbe. 
Genus Haplqcqnus nov. 
(kaploos, simple; honos , cone.) 
This genus is proposed to include trilobites closely related 
to Cyphaspis, but differing in not having isolated basal lobes 
on the glabella, and in having a less prominent axial lobe on 
the pygidium. 
Type, Batkyurus smithi , Billings. 
Cypkaspis ? galenensis, Clarke, is a second species, and it is 
probable that C ? brevimarginaia , Walcott, belongs here also. 
The genus Cyphaspis was proposed by Burmeister for a tri- 
lobite with a very prominent glabella, which was surrounded 
by a deep furrow, and which did not extend as far forward 
as did the glabella of Proetus. The front of the glabella is sep- 
arated from the marginal rim by a distinct roll, as is well shown 
in fig. 3 of Plate III of Burmeister's “Organization des Tri- 
