90 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVIII. 



8. 



9. 

 10. 

 11. 

 12. 

 13. 



14. 

 15. 



Leu;s I and II of male longer than the others, and end in claws; two forms of 



male, one with very large mandi) )les FdkuJIfer 



Legs I and II not longer, not ending in claws; one form of male only 7 



Body soft, weakly ehitinized, pale color lilroUusia 



Body harder, more strongly chitinized; more or less brown in co]or . .PterolicJnis 



Legs I and II of male with distinct sinne-like processes 9 



Legs I and II without such processes 12 



Leg III without a sucker, ending in a stout claw; rarely spines on tarsus.. l;;'(/ye-'^ 



Leg III with a sucker at tip 10 



Leg III larger than IV, with spines on tarsus Megninia 



Leg III scarcely as thick as IV 11 



Leg III plainly longer than IV Prolalges 



Leg III plainly shorter than IV Pferallopfes 



Leg IV larger than III 13 



Leg IV smaller than III 15 



Tip of abdomen of female entire, and usually of male; leg IV very short 14 



Abdomen of female and usually of male bitid at tip, often deeply so; l)ody slen- 

 der; leg IV rathei- slender AUoptes 



Suckers of tarsi small Xoloptes 



Suckers of tarsi large Syringobia 



Abdomen of male more or less bilobed at tip; leg III usually reaches beyond 



1 )ody , and has no teeth near ))ase Pteronijssus 



Abdomen of male entire; leg III usually does not reach the tip of body, and 

 has one or tw(j teeth near base on iinier side DermogJyphus 



111 Freyana some males have one 

 of the anterior legs, sometimes the 

 left, sometimes the right, greatl^^ en- 

 larged to aid in holding the female. 

 The hind legs arise nearer the middle 

 of the venter than in other genera, 

 and are very short. Two species have 

 Ijeen recorded from this country, 

 one, F. anxc/'ina Koch, on the snow 

 goose, and the other, F. capnt- 

 onedusx Trouessart, on the booby. 

 The latter species is sometimes over 

 1 millimeter long, one of the largest 

 species of the family. In Pterodectes 

 the body is elongate and slender, the 

 legs all of about equal development, 

 and in both sexes the tip of the abdo- 

 men is bilobed, in the female with 

 two stout bristles. There are dis- 

 tinct shields upon the dorsum. The 

 genus Allanalges {Pterocolm) is 

 scarcely different. Professor Hal- 

 ler recorded one species, A. gracile- 

 2)innatii.% from Canada. 



In ProctopJn/lIodes the body is also 

 slightly elongate, and the legs of 

 subequal size. The a))domen in the female is bitid at tip and with two 



172.— Alloptes microphjEthon, and ca- 



RONCLE. 



