536 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
fourth to seventh, ; i a pan the nent and ninth, 2” 
ae a of the 
3 
2, 2, 
tenth, eRe of the eleventh, 2 EEE of the spelt’ ahi the 
dorsal tibial spines equal; of the thirteenth, ee , the caudal dorsal 
tibial spine small; of the penult, ee claws 3; (anal legs missing 
in type) none of the coxae at all armed. 
Tibial process of penult legs of male dorsal in position; shorter and 
lower than in simplex, more crest like; not very conspicuous. 
Length near 20 mm. 
Locauity.— Mexico: Distrito Federal; Esclava (O. W. Barrett). 
Type, M. C. Z. 1742; one male. 
Closely allied with the preceding species but readily separated by 
differences in spining of legs (e. g. in total lack of coxal spines); clearly 
by differences in the position and form of the tibial lobe on penult 
legs of the male; and by differences in proportions, etc. 
LABROBIUS, gen. nov. 
Lateral marginal breaks of head very weak or obsolete. 
Antennae short or intermediate; articles from 29 to 57. 
Eyes composed of seriate ocelli. Single ocellus clearly differenti- 
ated. 
Prosternal teeth 2 + 2; line of apices from straight to a little re- 
curved. Spines slender, bristle like. Sinus distinct, more or less 
u-shaped. 
Posterior angles of ninth, eleventh, and thirteenth or of seventh, 
ninth, eleventh, and thirteenth dorsal plates produced. 
Coxal pores circular; uniseriate. 
Claw of female gonopods strictly entire as usual, spines stout, 
subconical, 2 + 2. 
Anal legs in male with fifth joint bearing at distal end on dorsal 
or dorsomesal surface a conspicuous, laterally compressed crest. 
Posterior coxae dorsally armed or else wholly unarmed dorsally 
but armed laterally instead. Dorsal spines of anal legs 1, 0, 3, 1, 0 to 
0, 0, 3, 2, 1; ventral 0, 1, 3, 2, 1; claws 2. Dorsal spines of penult 
legs 1, 0, 3, 2, 2 or 0, 0, 3, 2, 2; ventral 0, 1, 3, 3, 1. Dorsal spines of 
* first legs 0, 0,1, 1, 1 or.0,.0, 2, 1, 1; ventral, 0,.0, 0,:0, 0 t0.0):0,4 oa 
Length 10-13 mm. 
GENOTYPE.— Labrobius minor, sp. nov. 
In addition to the genotype and L. delus, sp. nov., L. sontus (Cham- 
berlin) and L. vuleani (Pocock) also belong in this genus. 
