134 Monograph of fJie Crustacea of the Cincinnati Group. 



shield ; lateral furrows Avell defined, and extending inward on eacli 

 side, about one third the entire breadth ; posterior lateral lobes a little 

 smaller than the next two on each side in front of them, and sometimes 

 nearly isolated by the furrows immediately before them, being so 

 oblique as nearly or quite to run into tile neck furrow before reaching 

 the middle ; succeeding two lateral lobes on each side, nearly trans- 

 verse ; anterior lobe larger, about twice as wide as long, rounded on 

 each side, and somewhat straightened across the front. Neck segment 

 well defined, arched upward, so as to be as high in the middle as any 

 part of the glabella in front of it, and Avider in the middle than at 

 either end ; neck furrow rather distinctly arched forward in the mid" 

 die. Cheeks sloping anteriorly and laterally from the eyes, with the 

 continuation of the neck furrow along their posterior margins strongly 

 defined, straight, transverse, and terminating laterally some distance 

 Avithin the margins, where they meet nearly at right angles a furrow 

 that passes forAvard on each side to the anterior end of the glabella ; 

 outside of the latter, a more sh.alloAV furrow also passes around the lat- 

 eral borders. Eyes of moderate size, scarcely as prominent as the mid- 

 dle of the glabella, situated their own length in adA'ance of the posterior 

 margins of the cheeks, and nearly the same distance from the front of 

 the same ; visual surface a little arched, and showing under a good 

 lens, when moistened, very minute reticulations, that seem to be 

 mainly seen through the thin crust. Facial sutiires starting at the 

 middle of the anterior margin of the head, and cutting rather close 

 around the anterior lateral corners of the glabella ; thence extending 

 backward, with a slight outward obliquity to the eyes, Avhere they 

 make slight curves (to form small, moderately prominent, palpebral 

 lobes) to the posterior end of each eye ; from AAdiich point they extend 

 outAvard at first Avith a slight forward obliquity, after Avhich they are 

 deflected backward andoutwai-d, so as to cut the lateral margins a little 

 in advance of the points Avhere the continuations of the neck furroAv 

 along the posterior margins of the cheeks Avould intersect the same if 

 continued outward. 



Thorax about twice as long as the cephalic shield, nearly as Avide 

 anteriorly as long, and distinctly trilobate ; axial lobe scarcely equal- 

 ing the breadth of the lateral lobes anteriorly, and proportionally a 

 little narroAver behind, but rather distinctly more prominent and 

 rounded ; segments eleven, nearly transverse, and regularly arched 

 upAvard. Lateral lobes a little flattened on top, nearly half Avay out- 

 Avard, at which point they slope oflT rather abruptly laterally ; i)leura3 

 straight and transverse for nearly half their length, Avhere they are 

 geniculated, obscurely subnodose, and curve downAvard and a little 



