432 REV. O. p. CAMBRIDGE ON NEW ARANEIDEA. [May 16, 



Thwaitesia? diversa, sp. n. (Plate XXXI. fig. 8.) 



Adult female, length 2 lines. 



This Spider differs in some respects from the type of the genus, 

 but whether sufBciently so to justify the formation of another genus 

 for it appears to be uncertain as yet. 



The normal indentations of the cephalothorax are less strong, and 

 the eyes of the posterior row are equidistant from each other, and 

 the height of the clypeus is equal to half that of the facial space ; 

 the legs also are shorter and rather stronger, and are furnished with 

 hairs only, but these are strong and of a bristly and even somewhat 

 spinous nature. 



The maxillae are very similar to those of the type ; but the labium 

 is distinctly hollowed at the apex. 



The cephalothorax, falces, maxillae, and labium are of a brightish 

 orange-yellow brown hue ; and the sternum is of the same colour, 

 with a dusky patch near its fore extremity. 



The legs are of a paler yellow hue ; the fore extremities of the 

 femora and tibise, with the genual joints and (more faintly) a por- 

 tion near the middle of the femora and tibise of the first and second 

 pairs, are red-brown, giving the legs an annulated appearance. 



The abdomen is large, and has its posterior extremity produced 

 into a strong but not very long hump. When looked at inprofile,the 

 distance from the spinners to the apex of the hump is rather less 

 than that from the spinners to the fore extremity (on the upperside) 

 of the abdomen. It is thinly clothed with hairs, and is of a pale dull 

 luteous yellowish-brown colour. The posterior extremity of the hump 

 is black ; and in other parts along the middle, at the back and on the 

 sides, there are blackish stripes, patches, and markings ; one also 

 underneath (between the spinners and the genital aperture) appears 

 to coutain a transverse slit, probably the opening into a portion of the 

 breathing-apparatus ; if this should prove to be so (of which I could 

 not satisfy myself suflaciently), it would probably be a good reason for 

 its separation into another genus. The genital aperture is nearly 

 round, not large, but placed on a transverse oval area and surrounded 

 outside again with a strong corneous-looking rim. The spinners 

 are short and compact. 



A single example in Mr. Traill's Amazon collection. 



Subfamily FhoroncidincB. 



Ogulnius, g. n. (nom. propr.). 



Cephalothorax abbreviated behind ; caput rather raised and pro- 

 duced, the ocular area including the whole of its anterior extremity ; 

 clypeus low, considerably less than half that of the facial space. 



Exjes unequal in size, the four centrals largest, and forming a large 

 trapezoid whose anterior side is much the shortest ; the lateral pairs 

 are placed obliquely on small tubercles, and the eyes of each are 

 contiguous to each other on either side. 



Legs projecting laterally from the sternum, moderately strong. 



