370 ON THE PEDIPALPI OF NORTH AMERICA. 



rounded off. The hands are large, and have only their superior and inferior edges 

 distinctly crenate. The fingers are robust and moderately long, with their opposing 

 margins armed with a single row of teeth, with larger ones at regular intervals on 

 one side of their distal portion. The feet are compressed. The tail is rather 

 robust. The first three joints have their superior and supero-lateral ridges sharply 

 serrate, and terminating posteriorly in a spine. In the fourth they are the same, 

 except that the terminal spinule of the supero-lateral crest is wanting. The first 

 four joints have infero-lateral and inferior crests, the former mostly distinctly, the 

 latter indistinctly, (except on the posterior segment,) serrulate. The penultimate 

 articulation is long, and armed with distinctly serrulate supero-lateral, infero- 

 lateral crests, as well as a single median inferior ; and on its anterior half, central 

 lateral ridges. Its form is that of a parallelopipedon thinned at its two extremities. 

 The superior surface of the last joint is triangular and complanate ; the inferior is 

 convex. The sting is very long, slender and gracefully curved. The sternal plate 

 is pentangular. 



Length of body, c? 10 lines, 9 12 lines; of tail, c? 16 lines, 9 14 lines. 



Hdb. — Cape St. Lucas, J. Xantus de Vesey. Smithsonian Museum. 



B. spinigerus. — B. dilute olivaceo-fulvus, fusco vittatus; cephalotliorace antico haud emarginato, medio 

 canaliculate) ; oculis lateralibus in serie curvata positis ; palpis modice robustis, marginibus valde 

 crenulatis; manibus nonnihil tumidis, lineis elevatis obsoletis; digitis nonnih.il elongatis, modice 

 curvatis, marginibus opponentibus et dentatis et crenulatis; abdominibus mediis nonniliil carinatis; 

 Cauda modice breve, robustissima, lineis elevatis denticulatis ; spiculo sine spinulo basali; pectinis 

 dentibus 20—25. PL 40, fig. 2, 2a, 26. 



B. spinigerus, Wood. Proc. Acad. Nat. Sci., April, 1863. 



The color of this species varies ; generally each abdominal plate has a dark brown 

 V or W-shaped marking, forming a continuous stripe on each side. This is obsolete 

 on the cephalothorax. But this distinctness of pattern is often lost, and the whole 

 body involved* in an olive-brown tint. The palpi closely resembles those of B. 

 boreus, but have the hand not so large, and the facets and elevated lines not so 

 strongly pronounced. The opposing margins of the fingers resemble those of that 

 species in their armature, but want the wavy outline. On each side of the abdomi- 

 nal median line are numerous small black tubercles, so arranged as to form more 

 or less prominent ridges. There is also a series of these on the posterior border of 

 each of the abdominal scuta. The legs and tail are of a dirty yellow color. The 

 anterior four caudal joints are short and very robust, the breadth of the first three 

 often equalling their length. These four joints are provided with denticulate 

 superior and supero-lateral crests. In the anterior three these are of nearly the 

 same length, and terminate distally in a small spine. In the fourth, the dorsal is 



