152 Annals Entomological Society of America [Vol. WV, 
than the first and the latter clearly narrower than the head. Average 
ratio between widths of head and first and tenth dorsal plates 68: 65: 74.3. 
A male has widths of head and first, third, eighth, tenth and twelfth 
dorsal plates to each other as 68, 65, 63, 75, 75, and 68. 
Length from 17 to 24 mm. A female 19 mm. long has antennz 
10.5-11 mm. long, anal legs 8.5-++ mm. long, and tenth dorsal plate 2.8 
mm. wide. Males have similar relative measurements. 
Type Locality: Fernwood, Mississippi. 
Known Localities: Mississippi (Fernwood, Canton and 
Byram. Author, collector, 1910). 
Although it has seemed impossible on the basis of any 
previously stated characters to maintain as distinct several 
species allied to L. mordax and L. vorax, through the use of 
characters not previously detected the writer finds it now an 
easy matter to discriminate between them. Such of this 
group of species, the larger forms dominating in the Southeast, 
as have the posterior angles of seventh, ninth, eleventh and 
thirteenth dorsal plates produced thus far known from the 
U.S., are, in addition to devorans and voracior, above described, 
the following: mordax K., transmarium K, vorax Meinert, tyran- 
nus Bollman, suprenans Chamberlin, and /atzeli Meinert. The 
writer’s previously expressed opinion that clarus McNeill was 
based upon immature specimens has been confirmed by an 
examination of the types of this species, these proving to be 
vorax in the pseudomaturus stage; mordax and transmarinus, 
merged by Bollman in spinipes Say, are clearly distinct; and 
study of types shows tyrannus and latzeli to differ from vorax 
which previously had been thought identical, the published 
diagnoses revealing no truly distinctive characters. 
Genus Sozibius gen. nov. 
Type—Lithobius tuobukus Chamberlin. 
The following species is placed here only tentatively. 
Sozibius pungonius sp. nov. 
Dorsum very light brown. Head cephalad of frontal suture and 
the caudal segments darker, somewhat orange colored. Antennz 
yellow. Venter and legs very pale, the posterior pairs bright yellow. 
Prosternum and ultimate ventral plates dark yellow. 
Antenne short composed of twenty-one articles of which the first 
six are long, the others shorter. 
Ocelli about eleven, small arranged in three curved and rather 
irregular series; thus, 1++5, 3, 2. 
Prosternal teeth 2+3. 
Angles of none of the dorsal plates produced. 
