CRUSTACEA. 
63 
Observations. The Calymene macrophtalma of Brongniart (Crustaces Fossiles, p. 
15, pi. i, figs. 4, 5. 1822) embraced much heterogeneous material, and included 
a specimen which is now referred to Dalmanites anchiops. Two of the diverse 
forms mentioned by Brongniart were from unknown localities in America; one 
of these was a plaster cast made from the specimen which subsequently served 
as the type of Asaphus laticostatus of Green. Of the others, one form {tab. cit., 
fig. 5), is the Calymene macrophthalma of Murchison, Phacops Brongniartii of Port- 
lock, and the Phacops latifrons of Burmeister; the other is the Phacops macrophthal- 
mus of Burmeister. The Asaphus Wetherelli, Green, which has been regarded 
by Burmeister (Organic, der Trilob., p. 90) as probably a young individual of 
Phacops anchiops, was undoubtedly an imperfect specimen of Dalmanites limulurus. 
Green, from the Niagara group. 
Dalmanites anchiops and its varieties show a divergence from typical forms 
of the genus Dalmanites {D. Hausmanni, D. pleuroptyx, etc.), in the coalescence of 
the first and second pairs of the glabellar lobes, a feature which places it under 
the group Chasmops of McCoy. In the typical species of Chasmops {Phacops) 
conicophthalmus, Sars and Boeck; Phacops macrurus, Sjogren, these united lobes 
are large, and upon the dorsal surface give no apparent evidence of the obso¬ 
lescent second glabellar furrows. D. anchiops in its usual- condition of preser¬ 
vation as casts of the inner surface of the test, shows traces of these furrows, 
but when the crust is retained, or upon casts of the dorsal surface they are 
quite obsolete The small basal or third glabellar lobes are usually quite 
distinctly separated from those in front, but occasionally show a tendency to 
coalesce with the others and form a single lobe on each side. In some species 
of Dalmanites {Phacops Lopatini, Schmidt, and Phacops Sibericus, Schmidt), this 
coalescence is complete, and for such variations the sub-generic term Monorakos 
has been recently proposed (Schmidt, Bull, de Tacad. imp de sciences de St. 
Petersb., vol. xii, p. 417. 1886). 
Distribution. Dalmanites {Chasmops) anchiops: Oriskany sandstone, Walpole, 
Province of Ontario, in association with Phacops cristata, var. pipa, Streptorhynchus 
{Orthis) hipparionyx, Spirifera arrecta, Rensselcxria ovoides. Upper Helderberg 
group. Abundant in the Schoharie grit, in the town of Knox and vicinity 
