204 THE CANADIAN ENTOMOLOGIST. 



NEW GENERA OF NORTH AMERICAN LITHOBIID^i 



BY RALPH V. CHAMBERLIN, UNIVERSITY OF PENNSYLVANIA, PHILADELPHIA. 



(Continued from p. 178 ) 



Genus Gosibius, gen. nov. 



Anterior margin of the prosternum wide. Teeth, 2 + 2 ; small, the 



line of apices clearly recurved ; ectal spines springing from a rounded 



nodule, long and slender, being much more slender than the teeth, but 



stouter than the bristles. 



Antenna long, the articles all long and slenderly cylindric. 

 Coxal pores circular, uniseriate. 



In the known species the last four pairs of coxae are armed laterally. 

 The penult legs bear two or three claws and the anal one or two. In 

 both males and females the anal legs are armed dorsally with 1,0,3,2,2 

 spines, as are also the penult. Characteristic also of this genus is the 

 presence on the tibiae of most of the legs (e.g., the 5th to 12th pairs), of 

 three ventral spines, as against but two in the related genera. The 

 posterior legs are short and slender, with the prefemur and femur, and also 

 sometimes the tibia, of anal pair more or less longitudinally furrowed 

 above : in the male the penult legs always unmodified, and the anal legs 

 also unmodified or with the femur alone modified, being then widened 

 and complanate and more distinctly furrowed dorsally. 



Gonopods of female^nearly as in related genera, the claw being large 

 and entire and the first article conspicuously excavated on mesal side of 

 base, which side is also strongly chitinized. Basal spines, 2 + 2 or 3 + 3. 



The species of this genus are less strongly narrowed cephalad than 

 those of Arenobius, and the first plate is nearly as wide as or wider than 

 the third. 



Type. — G. paucidens (Wood). 



Dist ribiit ioîi. — SouXhtxn California, etc. 



In addition to the type only one species, G. monicus, Chamb., is at 

 present known, with certainty, though mutilated specimens from Los 

 Angeles seem to represent a second. 



I. Owing to a mistake of our own, the several new species of Arenohinsy to 

 have been described below, have been published elsewhere by Mr. Chamberlin. 

 We regret the awkward division of the article which our error has necessi- 

 t .ted. — [Editor. 



July, 1912 



