ONISCOIDEA. 729 



paulo transversum, anticd stibtrwicatum, a segmento proximo partim 

 amplexum. Segmentwn thoracis primum majus, ultimum angulis 

 productum et acutum. Styli caudales abdomine parce longiores, rarno 

 majore triplo longiore quam minor, reversoscabriculo. 



Body somewhat shining, scarcely narrower in front, rounded. Abdo- 

 men suddenly much narrower than thorax, short, a little oblong, 

 sparingly pubescent, last segment very short, transverse triangular. 

 Head somewhat transverse, subtruncate in front, and setting deeply 

 into next joint. First joint of thorax largest; last with the 

 angles produced and acute. Caudal stylets scarcely longer than 

 the abdomen, branches very unequal, one three times longer than 

 the other, the longer finely reversed scabrous. 



Plate 48, ^.g. 1 a, animal, enlarged ; b, under view of abdomen of 

 male ; c, outer maxilliped. 



Found under stones, near Rio Janeiro, December, 1838. 



Length of male, six lines ; of female, eight lines. Colour, black, or 

 nearly black, with some irregular lighter spots (sometimes nearly 

 white) along the anterior portion of the thoracic segments, and also 

 along the median line of the abdomen, at times giving the animal a 

 dark grayish aspect. The head is not wider than half the next seg- 

 ment, and is nearly two-thirds encircled by it. Last abdominal seg- 

 ment slightly longer than preceding, low pointed behind ; the three 

 preceding segments laterally produced backward and acute. Eyes, 

 black, situated obliquely on the latero-anterior angles of the head. 

 Legs scabrous, the last pair spinous ; claw very short, on last pair not 

 longer than one-sixth the preceding joint. Abdominal lamellae, five 

 pairs ; the anterior smallest, bidentate at apex, the inner tooth longer. 

 The following pairs of lamellae elongate and acute near the median 

 line. A broad oblong oval plate between first and second pairs, which 

 terminates behind in two oblong styliform organs (in male) acute and 

 curved a little outward. 



Another specimen, mutilated in its antennae, resembled the above, 

 except that the abdominal plates were obtuse, instead of acute, and 

 the organ between the first and second pairs was wanting, indicating 



that it was a female. 



183 



