256 
PALAEONTOLOGY OF NEW-YOKK. 
Fig. 1 g. A fragment of a large buckler, having but two distinct rows of punctures in front of the 
glabella. 
Fig. 1 h. A portion of the thorax and caudal extremity, from the glazed slate, at Waterford. The long 
spine appears as if attached to the caudal extremity; but it is scarcely in a direct line with 
the axis of the specimen, and is not quite symmetrical on the two sides at its base. I am, 
therefore, inclined to regard this as a spine from the buckler, which has been accidentally 
placed in this position. 
I have not yet been able to find any marks of specific distinction among these fossils, 
though I have examined more than one hundred nearly perfect specimens, and as many 
fragments, from the slate and limestone. The small spine-like process at the base of the 
glabella has not been heretofore observed, but it will be found to exist in all perfect speci¬ 
mens ; the cause of its absence is fracture, which may often be obscure or indiscernible. 
I am indebted to Dr. Emmons for an opportunity of examining a beautiful collection 
of specimens of this species, from the shales of the Hudson-river group, at Loraine. Many 
of the small slabs are completely charged with them, and several hundreds were obtained 
in the space of a few feet. 
Position and locality. This species is found throughout the rocks of the Hudson-river 
group, occurring in the lower part of the same at Turin and Martinsburg. At Loraine and 
Pulaski, this fossil occurs in the higher parts of the group; and at Waterford, near Cohoes 
falls, in the glazed and plicated slates of the same group. It has likewise been found in 
one or two places in the Mohawk valley, in a similar position. (State Collection.) 
310. 1. OLENUS ASAPHOIDES. 
Pl. LXVII. Figs. 2 a, b, c. 
Elliptocephalus asaphoides. Emmons, Tac. System, 1844, pag. 21, fig. 1,2, 3. 
— — Id. Agr. Report, 1846, pag. 65, figs. 1. 2, 3. 
Compare Asaphus ( Ogygia) Buchii, Brongniart, Crust, fossiles, pag. 20, pl. 4, figs. 2 a b. 
Asaphus Buchii, Murchison, Sit. System, pag. 662, pl. 25, fig. 2. 
Ogygia ( Asaphus ) Buchii, Burmeister, pag. 69, pl. 1, fig. 2. 
Olenus of Dalman, Burmeister, &c.* 
Buckler semielliptical or subcrescent-form, with the posterior margins produced into 
sharp spines; eyes indistinctly marked; glabella lobed; direction of the facial suture as in 
* The species under consideration is either an Olenus or Ogygia, as the genera of this class of animals are now 
defined, and I therefore arrange it with the former for reasons to be given. The name Elliptocephalus could 
scarcely be admitted, since the E/lipsocephalus of Zenker is so well known in its application to a very distinct 
generic form. 
