366 ON THE PEDIPALPI OF NORTH AMERICA. 



however, no superior, and but a single median inferior crest. Its distal extremity is 

 furnished on its lower aspect with two curved series of denticules. One of these is 

 semi-elliptical; the other semi- circular. The last joint is large. Its superior surface 

 is triangular, flat, or even depressed, and provided with well developed articular pro- 

 cesses. Its inferior aspect is somewhat tuberculate, and is furnished with two obsolete 

 grooves, and a row of denticules around its proximal extremity. 



Length of body <^ § una 9 -f tail cT ! 9 § unc. 



The only specimens that we have seen were collected in Cuba, by Mr. Wright, 

 and presented by him to the Academy. It is possible that this species is not a native 

 of the United States. As our description is drawn up from a foreign specimen, we 

 append the original one of M. Gervais. 



" Scorpion de Lesueur ($. Lesueurii)." 



" Troisieme paire d'yeux lateraux sur la menie ligne que les autres, plus petite ; cephalothorax 

 ecbancre en avant, lissee, ainsi que F abdomen et le reste du corps sauf les carenes eaudales ; anneaux de la 

 queue epais et courts ; line carene medio laterale sur les premier, deuxieme et troisieme et en rudiment sur 

 la quatrienie ; une seule latero-supere au cinquieme ; vesicule plus grand que l'aiguillon, aplatie en dessus, 

 rugueuse en dessous; aiguillon subitement courbe ; une epine obtuse a sa base ; 8 dents au peignes ; main 

 cordifbrme a doigts courts, Fimmobile le plus court; couleur fauve testacc en dessus et sous la queue ; dessous 

 de l'abdomen et pieds blonds; quelques poils au palpes, aux pieds et <i la queue. Long, totale 0.050." 



Buthus exilicauda. — B. dilute aurantiaco-brunneus, .interdum obscure maculatus; dorso tuberculis 

 parvis asperato ; cephalothorace antico late sed haud profunde emarginato; palpis nonnihil 

 gracilibus, subelongatis ; manibus parvissimis; digitis valde elongatis. gracilibus, curvatis ; cauda 

 gracile, nonnihil subelongata ; spiculo modice longo, valde curvato, sine spinulo basali; pectiuis 

 dentibus fere 18. 



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



The cephalothorax is medianally canaliculate, and anteriorly broadly but very 

 shallowly emarginate. The lateral eyes are arranged in a straight or nearly straight 

 ' series. The palpi have their surface quite rough, and are somewhat elongate and 

 slender. The second article has four minutely crenulated crests, besides minute tu- 

 bercles on its anterior face. The third has five ridges, besides larger tubercles on 

 its front surface. The anterior aspect of the band is very convex. The posterior 

 border is ornamented by an obsoletely crenulate ridge. The opposing margins of the 

 fingers are armed with obliquely longitudinal imbricated rows of minute teeth, with 

 a series of distant larger ones on either side. The caudal surface is' rough. The first 

 joint has very minutely denticulate superior, supero-, median-, infero-lateral, and in- 

 ferior ridges. The next three articles have the same crests, except the median lateral. 

 There are generally no distinct ridges on the penultimate segment. The last joint 

 is short, and very narrow, but quite thick. Its superior aspect is not complanate ; 

 its inferior is strongly convex. The lower surface of the tail is generally marked 



