CRUSTACEA. 
133 
the reniform eyes, the absence of occipital lobes, the great length of the pygi- 
dium and the number of its annulations are all Phillipsioid characters. 
The species may ultimately prove to be a Carboniferous fossil, but any satis¬ 
factory determination of its age must await the acquisition of more complete 
material. 
Proetus Missouriensis, 
PLATE XXIII, PIG 32. 
Proetus Missouriensis, Shumard. Geol. Rept. Missoui-i, p. 196, pi. B, fig. 13. 1855. 
Proetus aurleulatus. Hall. Descr. New Species of Fossils, etc., p. 79. 1861. 
Proetus aurleulatus. Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 107. 1862. 
PJdllipsia Shumardi, Herrick. Bull. Sci. Lab. Denison Univ., vol. ii, jit. 1, jip. 58, 69, pi. vii, fig. 14. 1887. 
This species is noticed here in order to call attention to its correct determina¬ 
tion and its proper synonymy. The original of Mr. Shumard’s Proetus Missouri¬ 
ensis, described from the Lithographic limestone of Missouri, formerly regarded 
as of Upper Devonian age, is apparently identical with the detached cephala 
and pygidia from the Waverly sandstones of Licking county, Ohio, which were 
described in 1861 under the name Proetus auriculatus, Hall. Recently an en¬ 
tire individual of the species from Licking county, Ohio, has been described 
by Herrick {loc. cit.), under the term Phillipsia Shumardi. The change of name 
proposed by this author arises from the consideration that if the fossil belongs 
to the genus Phillipsia, the designation Phillipsia Missouriensis would be inad¬ 
missible as this name had been used by Shumard for a species from the coal 
measures at Lexington, Missouri, described in 1858, (Transactions St. Louis 
Academy of Science). Without entering into a discussion upon the right of 
priority under these circumstances to the specific term Missouriensis, the 
evidence, afforded by the entire specimen of the species, points distinctly to the 
fact that the genus to which it belongs is Proetus and not Phillipsia. The form 
of the glabella is in some respects similar to that of certain species of Phillipsia, 
being somewhat expanded anteriorly, the fourth lateral furrows strong and 
reaching to the occipital furrow, the third and second short and the first 
obsolete. Such variations frequently occur within the limits of the genus 
Proetus (P. canaliculatus, P. granulaius, P. crassimarginatus). The occipital lobes, 
