undescribed Genera and Species of Araneidae. Ill 



Mandibles very powerful, convex in front, diverging widely 

 at their lower extremities, and armed with a long moderately 

 curved nail, and two rows of teeth on the inner side. Those 

 of the male have an obtuse, conical prominence near the in- 

 sertion of the nail, which latter appendage has a small inden- 

 tation about the middle externally, and a corresponding pro- 

 jection, or minute tooth, within. 



Manduculus ambiguus, 



Cephalothorax rather large, convex above and glossy ; it is 

 of an oval form truncated in front, with an indentation in the 

 medial line of the posterior region ; the colour is light reddish 

 brown, with a black band along the middle, one on each side, 

 just above the margins, and a short black streak directed 

 backwards from each lateral pair of eyes. The pectus is 

 heart-shaped, and rather darker coloured than the cephalo- 

 thorax. The colour of the mandibles is light reddish-brown, 

 that of the maxillae and lip being dark red-brown. Legs and 

 palpi yellowish-brown ; they are sparingly supplied with hair, 

 but the former are destitute of spines. Each tarsus has three 

 claws at its extremity; the two superior ones are finely pecti- 

 nated, and the lower one is abruptly inflected near its base. 

 A single claw, pectinated about one third of its length, (the 

 last tooth of the series being much the longest,) terminates each 

 palpus. Abdomen oval, projecting a little over the base of 

 the cephalothorax; the colour is yellowish-brown, above irre- 

 gularly bordered with black ; a narrow longitudinal band of 

 pale yellow, having its anterior half bordered with black, and 

 comprising a slender black streak, occupies the medial line. 

 Along each side extends a broad band of dull yellow, which is 

 palest on the upper edge, and is tinged with light brown be- 

 low. Underneath the abdomen is yellowish-brown, with a 

 band of a darker hue along the middle, bounded on each 

 side by a faint yellow line. The plates of the spiracles are 

 yellow. This species varies considerably in colour. 



Length, from the anterior part of the cephalothorax to the 

 extremity of the abdomen, jth of an inch ; length of the ce- 

 phalothorax \ ; breadth r \ ; breadth of the abdomen £ ; 

 length of an anterior leg f ; length of a leg of the third 

 pair J, 



The male, which is smaller than the female, has the abdo- 

 men more distinctly marked; the upper part being almost 

 black, and the medial and lateral bands nearly white. The 

 third joint of the palpi is strong and very short; the fourth is 

 dilated regularly to its anterior extremity, which is truncated ; 

 and the fifth has two slender apophyses, the shorter one at- 



