32 PROCEEDINGS OF THE NATIONAL MUSEUM vol.86 



mucro. In most of the genera there are two setae at the apex of the 

 segment, but in Platydere and Leiodere, at least, the number is in- 

 creased to four, six, or eight setae. No specimens of Paiteya or 

 Choctella have been examined, and in the single specimen of Endere 

 all setae have been lost. 



In all genera the anal valves are without thickened margins, are 

 evenly inflated, meet at a reentrant angle, and each has two setae 

 near the opening. The preanal scale usually is nearly three times 

 as broad as long, and each lateral angle is covered by a small process 

 from beneath the margin of the last segment. 



The first pair of male legs of Paiteya^ Nannolene^ and Camhala are 

 reduced in size and 6-jointed, and the two latter genera lack a claw 

 on the outer joint; instead this joint is short and rounded at tip in 

 Nannolene, while in Ganibala the inner side is deeply excavated from 

 near the base to the apex. In the other genera of which males are 

 known the first male legs are normal as to structure but frequently 

 reduced in size. 



The males of Nannolene, Tridere, Pharodere^ and Canibdla have 

 lobes of various types on some of the joints of other legs in front 

 of the gonopods, but in the other genera of which males were exam- 

 ined none of the pregenital legs are lobed. 



From the foregoing brief delineation it is seen how inconsistent 

 are the characters among the genera, and the following key to the 

 genera of the family Cambalidae was prepared without attempting 

 a natural arrangement. Diagnostic characters for the recognition of 

 the genera of the family Cambalopsidae are given on page 57. 



Family CAMBALIDAE 



KEY TO THE GENERA OF CAMBALIDAE IN THE UNITED STATES 



I. Eyes present. 



1. Body stout, as in Spirobolus Choctella Cliamberlin 



Body slender, as in lultt.s 2 



2. Last segment projecting beyond anal valves in a distinct 



mucro ; clypeal setae scattered Tridere, new genus 



Last segment ni>t mucronate ; clyijeul setae in a transverse row .3 



3. Repugnatorial pores beginning on segment 6 Nannolene BoUman 



Repugnatorial pores beginning on .segment 5 4 



4. Dorsum with 2 indefinite crests between poriferous prom- 



inences Titsona Chamberliu 



Dorsum with 4 distinct crests between poriferous carinae 5 



5. Eyes with 4 to 8 ocelli in a single series ; first pair of male 



legs clawless Cambala Gray 



Eyes with 9 or 10 ocelli in 2 or 3 series ; first pair of male 

 legs with claws Paiteya Chamberlln 



