190 REVIEWS—CONTRIBUTIONS TO PALZONTOLOGY. 
bratula, are also described. These have a punctate shell-structure, 
but the internal characters have not been made out. 
A considerable portion of the work before us, is devoted to des- 
criptions of new goniatites and related forms, from the Hamilton 
Shales and other Devonian strata of New York. We may attempt 
an analysis of these, in another number of the Journal, but the large 
Space occupied by other articles in the present number, compels us to 
pass them by with this brief allusion. Well-executed figures are 
given of most of the species. 
Towards the close of Professor Hall’s Report, we have some addi- 
tional remarks on the trilobites of the “ Quebec shales” of Georgia, 
Vermont. These forms, it will be remembered, have given rise to 
much recent discussion, both on this continent and in Europe, and 
have made known to us the undoubted presence of an American 
“primordial zone.’ These trilobites have hitherto been referred to 
the genus Olenus (or, by Professor Hall, to Olenus and Peltura), but 
the author now considers them entitled to the rank of new and dis- 
tinct genera, upon which he bestows the names of Barrandia and 
Bathynotus. The species formerly referred by him to Peltura he 
places under Bathynotus, and the two other species under Barrandia. 
This latter genus is undoubtedly a legitimate one, holding an inter- 
mediate place between Paradoxides and Olenus. It differs from 
Paradoxides, more especially, by the anterior contraction of the 
glabella; and from Olenus by its contracted pygidium, this latter 
beg apparently composed of a single article, without the slightest 
trace of side lobes. In Barrandia, moreover, the third pleure are 
produced beyond the others. It appears to us, therefore, that this 
genus must hold good, so long as Paradowxides and Olenus are kept 
distinct ;* but the two species placed under it, seem, on the other 
hand, to be identical. Considering the crushed state of the form 
referred to B. Vermontana, no certain conclusions can be drawn from 
the glabella, and the rounded anterior lobe of the glabella of B. 
Thompsoni might undoubtedly be so distorted by pressure as to produce 
the appearance exhibited by the other example. The produced horns of 
the head-shield are certainly much shorter in one form than in the 
other, but that is a character of no specific value, as exemplified by 
Asaphus Canadensis and other species of trilobites. The proposed 
genus Bathynotus may likewise prove to be well founded, but the im- 
* The name Barrandia has already been applied, however, to a doubtful genus, by McCoy. 
