PROCEEDINGS OF THE NATIONAL MUSEUM 



Figure 16. — Thalkethops grallatrix, holotype: a, typical spine, the spinous process arming 

 tiie coxopleuron of grallatrix; b, a straight mucro; c, a curved mucro; d, a lanceolate 

 setae; e, f typical setae; g, a typical leg spur or calcar. 



rounded ; all articles fmely dorsally setose ; pref emur on each side with 

 sparse stout lanceolate (see note 3, p. 13) setae, ventrally with a 

 linear series of 7 short stout and pointed ankylosed mucrones (see note 

 3, p. 13) and a few scattered fine setae; femur ventrally with 12 

 ankylosed mucrones, its sides with lanceolate setae; tibia ventrally 

 with a row of 1 1 mucrones, without lanceolate setae, subdensely with 

 long fine setae ; first tarsus ventrally with one hooked firmly ankylosed 

 (nearly spiniform) mucro; second tarsus proximoventrally excavate, 

 without mucrones or lanceolate setae, with numerous long fine setae; 

 pretarsus long, thin and curved, without accessory claws. 



Key to the Scolopendromorph Genera of America North of Mexico 



The key given below should facilitate the identification of all 

 scolopendromorph genera and obligate higher categories presently 

 known to be represented in America north of Mexico.^ In addition, 

 I have included and identified by daggers (f) those few genera com- 

 mon to adjacent regions to the south, chiefly Mexico, whose presence 

 within our area may eventually be demonstrated. Following the 



« Since the preparation of this manuscript Professor Ohamberlln has written me of his discovery of a new 

 Oalifornian Ethmostigmus; this is the first record of the genus In North America. At the time of this writing 

 his description of the new species was not published. 



