CRUSTACEA. 33 



convex bearing a pair of short lateral furrows which terminate centralis in 

 two conspicuous depressions or pits, bounded posterior^ by a low sulcus, 

 beyond which is a linguiform extension bearing upon its margin five spinules, 



one of which lies on the axial line, with two on either side. 



Distribution. "Lower horizon of the Devonian limestone. Comb's Peak, and 



on the divide at the head of the Reese and I!err\ Cat Eureka District, 



Nevada.' 1 (Walcott, he. cit.) 



•'<> l; ONUR A. n. s.-G. 

 Dalmanites (Cokonura) aspectans. 



PLATE XII. FIGS. 1 11. 1.;. 



Asaphus aspectans, Conrad. Fifth Ann. Rept. Pal. N. *i .. y. 49, fig '.>. 1341. 



Asaphus? denticulatus, Conrad. Fifth Ann. Rept. Pal. N. ■> .. p. t8. 1841. 



Dalmania adspectans (in error). Hall. Deser New Species if Fossils, efc p.60. 1861. 



Dalmania Helena, Hall. Deser. New Species of Fossils, etc., p. 61. I 



Dalmania adspectans (in error), Hail. Fifteenth Rept. N. V State Cab Nat. Hist., p. 88. 1862. 



Dalmania Helena, Hall. Fifteenth Rept. N. Y. State Cab. Nat. Hist., p. 89. IS62 



Dalmanites Ohioensis, Meek. Pi Acail. Nat. Sci. Phil., p. 91. 1871. 



Dalmanites Ohioerisis, Meek. Pal. Ohio, vol. I. p. 234, pi. xxiii, fig. I. 1st:;. 

 Dalmanites denticulatus, Hall. Illustrations of Devonian Fossils, pi. x, fis<-. I. 1876. 

 Dalmanites aspectans, Hall. Illustrations of Devonian Fossils, pi. xiii, figs. 6 8. IS76. 

 Dalmanites Helena, Hall. Illustrations of Devonian Fossils, pi. xiii. figs. II II. 1876. 



Tins species has been observed only in detached portions of the exoskeleton. 

 The pygidia which have been described tinder the specific designations 

 Dalmanites Helena and D Ohioensis (op. cit.), are not uncommon in the 

 Corniferous limestone of New York and Ohio, and associated with them 

 are fragments of large cephala, which presumptively can belong to no 

 other species. Such a fragment of the cephalon, consisting of a free 

 cheek retaining the visual surface of the eye. served as the original 

 of the Asaphus aspectans of Conrad: more recently a larger fragment, also 

 retaining the greater portion of the eye and agreeing in ail particulars with 

 Mr. Conrad's type, has been found in the Corniferous limestone at Columbus, 

 Ohio, associated with the pygidium of I). !/<:' There is no other 



♦Through tin; kindness of Dr. .1. S. Newberry this specimen has 1 n made availabli Ebi use in the 



revision of these species. 



