NO. 2130. NORTH AMERICA RHAPHIDOPHORINAE—CAUDELL. 677 



The forms referred to Phrixocnemis are, for the most part, rather 

 closely allied, and three of them — socorrensis,franciscanus, and serrata — 

 were described by Mr. Rehn from the Snow collection, in Kansas, where 

 the types are deposited. Aside from the three above-mentioned 

 species, the types of all our forms have been studied and the following 

 key drawn up for their separation : 



KEY TO THE SPECIES OF PHRIXOCNEMIS. 



1. Apical two dorsal spurs of the posterior tibiae about twice as long as the tibial 



depths and separated from each other by a distance scarcely one-half as great as 



the length of one of them longispinosus, new species. 



Apical two dorsal spurs of the posterior tibiae not or but little longer than the tibial 

 depths and separated from each other by a distance about as great as, or greater 

 than, the length of one of them (fig. 22) 2, 



2. Upper outer calcar of the posterior tibiae apparently one-half or more longer than 



• the tibial depths, by actual measurement fully twice as long. 



obesus, new species. 



Upper outer calcar of the posterior tibiae apparently not or barely longer than the 



tibial depths, by actual measurement sometimes as much as one and one-foxirth 



as long 3. 



3. Posterior tibiae armed beneath with a single median spine near the tip; posterior 



femora of the male armed beneath with one or more distinct spines and the 

 corresponding tibiae decidedly bowed. 



truculentus Scudder. (? inhabilis Rehn.) 



Posterior tibiae armed beneath with more than one spine, the apical two situated 



one on each side of the median line; posterior femora of the male armed beneath 



with serrations or tubercles only and the corresponding tibiae almost or quite 



straight 4. 



4. Ventral outer calcar of the posterior tibiae not or but little more than one-half as 



large in general bulk as the median one; the ventral spurs usually correspond- 

 ingly small 5. 



Ventral outer calcar of the posterior tibiae larger, in adults two-thirds or more as 

 large in general bulk as the median one, the ventral spurs correspondingly 

 larger vierecki Rehn. 



5. Posterior femora of the male with some minute blisterlike tubercles on the outer 



face about and just beyond the middle and below the median line; ventral teeth 

 on the outer margin of the hind femora of the male bluntly acute-conical. 



oregonensis, new species. 



Posterior femora of the male smooth on the outer face, the teeth of the lower outer 

 margin sharply acute neomexicanus Thomas. 



Unplaced socorrensis Rehn, franciscanus Rehn, and serratus Rehn. 



PHRIXOCNEMIS LONGISPINOSUS, new species. 



Description. — (Female, the male unknown.) Form moderately 

 robust. Anterior tibiae unarmed above, armed beneath on both 

 margins with four stout movable spurs and apically on each side 

 with a similar spine situated laterally and near the dorsal surface; 

 middle tibiae armed as in the anterior ones, and in addition armed 

 above with three pair of spines similar to the ventral ones; hind tibiae 

 armed beneath on the median line with a couple of small spines on 

 the apical third, above armed with five spines on each margin and 

 with a few smaller_ serrations between them, the last dorsal spur on 



