160 Annals Entomological Society of America [Vole 
First dorsal plate large, closely embracing caudal portion of head. 
Anterior and posterior lateral angles rounded, the lateral margin be- 
tween them extending obliquely caud-oventrad, rather, long, somewhat 
incurved. Anterior margin incurved at middle curving out convexly 
on each side and then again at sides incurved bow-shaped. A fine 
transverse sulcus subparallel to the anterior margin and some distance 
from it and a second one submedian in position. 
Subsequent segments with a longitudinal furrow at level of pore, 
this more distinct on cephalic portion of segment. A transverse sulcus 
in front of median suture. Prozonites striate throughout, the main 
segment strongly striate beneath and on sides below level of pores. 
Dorsum a little depressed; a weak longitudinal depression each side of 
middle, leaving mesal portion a little elevated. 
Anal scutum considerably exceeded by the anal valves; caudal 
division short, widely and evenly rounded, set off or limited from major 
portion in front by a transverse sulcus. Caudal margin with two 
pairs of long sete. 
Anal valves elongate, their free margins elevated. Each valve 
bears near its mesal margin a long seta at caudal and second one near 
middle of length in a furrow or sulcus which curves from mesal margin 
first laterad and then latero-cephalad. 
Anal scale very short; caudally weakly convex, anteriorly strongly 
so; antero-lateral angles rounded, but not so the caudo-lateral ones. 
Legs moderately long and slender; claws long, not robust. 
Segments of body forty-five. 
Length 11-12 mm.; width as .5-.5 mm. 
Locality: Pacific Grove, Cal. (April, 1911, author.) 
One specimen secured under a stone in an open field near 
the Hopkins Laboratory. 
Family CAMBALID&. 
Genus Titsona gen. nov. 
Eyes well developed, each consisting of a number of ocelli arranged 
in a single series parallel with anterior margin of the first dorsal plate. 
Antenne short, very slender proximad but strongly enlarged distad, 
clavate; the fifth and sixth articles conspicuously and abruptly thicker 
than others. The third, fifth and sixth articles longest, not much 
differing in length from each other; second and fourth articles subequal. 
Gnathochilarium nearly as in Paiteya. Promentum triangular, 
completely separating the laminz linguales which are attenuated prox- 
imad to an acute angle. Mentum large, widening proximad. 
Body strongly constricted from head and first segment to region 
of fifth and sixth segments, from where it again increases in width 
caudad. 
First dorsal plate very large, extending over caudal portion of head 
from which the lateral portions extend free. 
