10 PROCEEDINGS OF THE NATIONAL MUSEUM vol. in 



11a. Legs 1-21 each without trace of tarsal division. Sternital cross-sulci 

 usually apparent; submarginal sulci typically pronounced. 



Genus Kethops 

 116. Legs 1-21 each with a tarsal suture delineating a proximotarsus and a disto- 

 tarsus. Sternital cross-sulci absent; submarginal sulci absent. 



Thalkelhops, new genus 

 12a. Each coxopleuron with a prominent ventroposterior spinous process. 



Genus Anethops 



126. Each coxopleuron without such a process, its posterior border essentially 



straight Genus Cryptops 



Distribution of Genera 



SCOLOPENDRIDAE 



Scolopendra: There are apparently fewer than half a dozen species 

 in North America; of them three are quite common, viz, viridis ^&y, 

 in the Southeastern Atlantic, South-Central, and apparently in some 

 Western States; polymorpha Wood, in the States west of Missouri; 

 heros Girard, throughout most of the Southern States across the 

 continent. In addition, a number of Tropical or Pantropical species 

 are frequently intercepted at seaports; e.g., alternans Leach, subspinipes 

 Leach, and morsitans Linne; none is known to be established within 

 North America. In general, distribution of the genus in North 

 America is different east and west of about long. 95° W., as follows: 

 East of long. 95° W., from the gulf coast north into southern Missouri, 

 Illinois, and Kentucky {heros and viridis), up the Atlantic Coastal 

 States from Florida as far north as southern Virginia {viridis) ; west of 

 long. 95° W., throughout the Southwest {heros, polymorpha, and 

 perhaps viridis) , up the Pacific Coastal States as far north as Washing- 

 ton {polymorpha and heros extending evidently only into California 

 and Utah), throughout all but the most northern Montane and Plains 

 States {polymorpha and possibly heros). Both heros and polymorpha 

 have been reported from Mexico, but whether the true viridis occurs 

 there, in my opinion, remains to be settled. 



Arthrorhabdus: One species, pygmaeus (Pocock), has been recorded 

 infrequently from New Mexico, Texas, and Arizona. It undoubtedly 

 also inhabits adjacent Mexico. 



Hemiscolopendra: Only punctiventris (Newport) [= Cormocephalus 

 {H.) punctiventris (Newport) of authors] is believed to inhabit 

 North America. Quite common east of the 95th meridian, viz, from 

 just south of the Great Lakes to the gulf coast and Southeastern 

 Atlantic States where it is extremely prevalent, on the Atlantic coastal 

 plain northward into Virginia, Pennsylvania, New York, and New 

 England; not known to occur west of about long. 95° W., in the 

 United States. 



Otostigmus: This genus is common to all Tropical and most 



