142 Monogj-a'ph of the Crustacea of the Cincinnati Growp. 



Genus Dalmanites — (Emmerich, 1845). 



"General form, hucUer, glabella, eyes, and eye lines, as in Phacops, but 

 the latter lobes of the glabella more equal ; not contractile ; thorax of 

 eleven segments; pleuri'pedes curved backward, and generally pointed 

 at their extremities, facets very long, narrow rhomboidal, slightly de- 

 fined ; pleural groove strong, slightly sigmoid and oblique (not angu- 

 lated) ; pygidium elongate, generally pointed, axis with from twelve to 

 twenty -two segmental furrows, sides with fewer (about half the num- 

 ber) strong ribs, usually duplex, confluent at their ends with the thick- 

 ened entire margin ; hypostoma with a dentate edge." 



Dnlmanites Carleyi — (Meek, 1872). 



Cephalic shield about twice as wide as long, rounded in front, and 

 more or less straight behind, so as to present a nearly semi-circular 

 outline, exclusive of the produced posterior lateral extremities; which 

 are about as long as the glabella, rather broad anteriorly, and tapering 

 rapidly to the posterior ends. Glabella Avide in front and rapidly nar- 

 rowed behind, defined by a moderately distinct furrow on each side, 

 and not very prominent at any point ; anterior lobe comparatively 

 large, transversely elliptical or sub-rhombic ; lateral lobes small, and 

 sepai-ated by furrows that extend inward, so as to leave only a very 

 narrow central space ; anterior pair each sub-trigonal, about twice as 

 large as the middle lobe, which is transversely ovate, while those of 

 the third or posterior pair are smallest ; neck furrow moderately well 

 defined, and continued as posterior marginal furrows of the cheeks 

 nearly to their outward margins; occipital segment comparatively 

 rather wide anterio-posteriorly, and elevated and convex in outline be- 

 hind ; palpebral lobes ascending and narrowing rapidly outward to the 

 summit of eyes. Cheeks sloping laterally from the eyes, rather ab- 

 ruptly, to a shallow marginal furrow, that is continued so as to form a 

 very narrow margin around the front of the glabella. Eyes moder- 

 ately large, situated full half their length from the posterior margins 

 of the cheeks, and elevated somewhat above the height of the glabella, 

 truncato-subconical in form, the visual surface curving round, so as to 

 form about three fourths of a circle at its base ; lenses of compara- 

 tively moderate size, showing about seven in a vertical row at the mid- 

 dle, and twelve or fourteen in the longest oblique rows ; surface of an- 

 terior lobe of glabella showing small obscure granulations ; other parts 

 of the cephalic shield nearly smooth, or less distinctly granular. 



