184 [October, 



K. sonoriense. Testa modice convexa, postice latiore, antice et postice de- 

 clivi, margine antice et postice dispanso, medio declivi; dorso indistincte 

 tricarinato, carina intermedia vertebrali evidentiore, alarum canali leviter 

 exarata, prope rudimentali. Cauda unguicnlata. 



Hah. In the northern part of the province of Sonora. 



Skin black, head and neck large, above mottled and spotted with whitish, be- 

 neath whitish, varied in the same manner with dusky; jaws horn-color, varied 

 with black, the upper jaw hooked and emarginate ; irids dark brown ; chin with 

 two tolerably large warts on the fore part. Fore legs above greyish dusky, with 

 three plica? or large scales; feet beneath scaly ? hind legs with three large scales 

 near the heel ; hind part with two large patches of rounded echinate scales. 

 Tail sulcate beneath, with a large and strong, rather blunt nail, and six rows of 

 small upright pointed papillae, and a few smaller ones round the anus. Shell 

 cinereous brown, with some very faint radiating marks of darker, and some 

 indistinct concentric striae on the plates : it is elongated oval, a little widened 

 behind, moderately convex, declivous both before and behind, the anterior and 

 posterior margin expanded, the middle declivous ; very slightly tricarinate on the 

 back, the intermediate carina more apparent, particularly before and behind, 

 the lateral ones obsolete and scarcely to be traced except on the two last lateral 

 plates. Vertebral plates imbricate, the first triangular, with its apex truncate, 

 its base straight and applied only to the first marginal, second, third and fourth 

 urceolate hexagonal, the second longer than either of the two others, the fifth 

 heptagonal, the upper face short subtridentate, the anterior lateral one much 

 longer than the others, the posterior lateral short and perpendicular to the basal, 

 which are a little curved, first lateral unequally quadrilateral, the lower side 

 curved and with four facets, second and third transverse, pentagon?], fourth 

 quadrangular, the posterior lateral angle widely and deeply emarginate so as to 

 give to the figure another curved side, by which it becomes pentagonal : margin 

 narrow, expanded in front, declivous in the middle, the three last plates expanded 

 and the caudal one again declivous, nuchal plate oblong four-sided, the second a 

 little wider than the first, third and fourth, the fifth, sixth, seventh, eighth and 

 ninth are wider and somewhat angled on the upper face; all these are oblong, the 

 tenth or penultimate is wider than any, its upper face is rounded and deeply and 

 widely emarginates the posterior basal angle of the fourth lateral, and is applied 

 on the upper part of its posterior face to the last vertebral, giving to lhat plate 

 its pentagonal form. Sternum jointed before by a ligament and behind by a suture, 

 not entirely closing the box of the shell ; before bluntly rounded, behind emar- 

 ginate, the plates concentrically striate, gular plate large, equilaterally triangular, 

 the base rounded, pectorals oblong quadrangular, outer side a little wider than 

 the inner and curved, the two exterior angles right, the lower one projecting a 

 little beyond the brachials, the anterior interior angle very obtuse, the remain- 

 ing one very acute ; brachials triangular, the apex blunt ; abdominals quad- 

 rangular, the outer side a little curved ; femorals quadrangular, the inner side 

 much shorter than the outer, posterior side oblique, outer side curved, the ante- 

 rior straight, the posterior exterior angle projecting a little beyond the caudals 

 which are right-angled triangular with the base rounded. 



Length 4.4, breadth 2.1, height 1.3 : sternum length, 3.7- tail 1.4. 

 This species, which has the shell much less elevated than any other which I 

 have seen, appears to be intermediate between this group and the next, so much 

 so, that I long hesitated where to place it. The points of resemblance, however, 

 whieh it had in common with the pennsylvanicum being more numerous than 

 those which belong to the orforatum, led me at last to arrange it with the former. 

 I may have been wrong in doing this, but if so, there is not much harm done. 

 The K. sonoriense was brought by my son along with many other interesting 

 animals from Tucson in Sonora; there can be but little doubt of its being found 

 likewise in California. 



Group III. Sternum narrow, subcruciform, valves joined to the abdominal 

 portion of the chest by sutures, the lateral teeth of which are so large as to 

 admit of but little motion, especially in the posterior one; wings long and narrow 

 without any groove on the inner part, tail unarmed. 



