S. J. Smith on American Crustacea. 129 



tero-lateral angle, which is obtuse and not at all prominent. The lat- 

 eral border is marked by a sharply upturned and finely denticulated 

 margin, which is arcuate anteriorly so that the breadth of the carapax 

 is considerably less between the antero-lateral angles than a little pos- 

 tei-iorly, and the posterior portion is strongly incurved and terminates 

 opposite the cardiac region. The posterolateral border is crossed by 

 an oblique raised line or plication. The inferior orbital margin is 

 finely toothed and the jugal region is rough and hairy. 



The larger cheliped is stout, and the length of the hand in large 

 specimens is nearly or quite three times as great as the length of the 

 carapax. The anterior surface of the merus is smooth, narrowly tri- 

 angular in outline and its margins are nearly straight, the inferior 

 armed with minute tubercles, and the superior with slender tubercles 

 on the distal portion ; the upper surface is roughened with shorty irreg- 

 ular, transverse rows of small tubei'cles. The superior surface of the 

 carpus is covered with depressed tubercles, the proximal portion of 

 the inner edge is tubercular and the inner surface is crossed by an ob- 

 lique ridge armed with tubercles. The basal portion of the propodus 

 is much shorter than the digital portion, and its superior and exterior 

 siirface is covered with depressed tubercles, which are large and sepa- 

 rated by smooth spaces on the upper portion, but below are smaller 

 and crowded, and, along the inferior border, almost obsolete ; the inner 

 surface is armed, on the inferior border, with a ridge of large tubercles 

 extending from the base of the propodal finger obliquely upward to 

 the border of the deep depression into which the carpus folds, and 

 there are also a few tubercles between this depression and the base of 

 the dactylus, and a line of tubercles extending upward, from the inner 

 edge of the propodal finger, parallel to the base of the dactylus ; the 

 superior edge is tuberculose and has a crenulated margin on the out- 

 side and the inner margin is curved downward at the extremity of the 

 depression into which the carpus folds ; and finally, the inferior edge 

 is smooth and rounded, but with a slight margin on the outside. The 

 propodal finger is nearly straight ; the inferior edge is smoothly round- 

 ed, the prehensile edge is broad and ai-med with marginal lines of 

 small tubercles, and a median one of irregular tubercles, of which one, 

 about the middle of the finger, is very much larger than the rest ; and 

 the tip has an excavation into which the dactylus fits. The dactylus 

 is much curved, especially toward the tip, which hooks considerably 

 by the tip of the propodal finger, and the prehensile edge is much as 

 in the other finger, but the tubercles of the median line are nearly 

 obsolete, except two or three large ones near the base, and as many 

 more between the middle and the tip. 



Trans. Connecticut Acad., Vol. II. 9 March, 1870. 



