April, 1919 Bulletin of the Brooklyn Entomological Society. 59 
proximally there are four bristles, two outside and two inside, 
and distally there are two outside. Both the mid and hind tibiz 
bear two lateral rows of bristles as follows: mid tibia, lateral 
row nearest dorsals, 6, second row, nearly median, 5 ; correspond- 
ing rows on hind tibia, 6, 5. On both tibiz there is a short row 
distally just inside the anterior margin of 5 and 6 respectively. 
The tarsal segments bear the following comparative measure- 
ments: 
Tarsus. Segments 1-5. 
I 20 18 13 Il 30 
II 36 2, 16 13 Bil 
III 65 45 30 16 36 
The longest apical tibial bristle of the hind leg reaches the 
apex of the first tarsal segment, but none of the apical bristles 
of the first or second segments reach the apex of that following. 
The fifth segment of the anterior and mid tarsi have each four 
pairs of lateral and additional pair placed between the proximal 
laterals. The fifth segment of the hind tarsus has but four pairs, 
all lateral. 
Modified Segments——The eighth sternite bears on each side 
eleven bristles, of which three are longer and heavier than the 
others. The process of the clasper is bilobed, the upper lobe 
nearly twice as long as the lower, which is nearly as long as 
broad and is truncated parallel with its base. Each lobe bears 
one heavy bristle near its outer margin. There are about forty 
smaller hairs on the two lobes. The exopodite bears no heavy 
bristles, but has about fifteen hairs along its outer margin. Up- 
ward it is produced to a rather sharp point. The ninth sternite 
bears at the apex a row of spines, apparently four in number; 
however, all are undoubtedly double. Proximally to this row 
are apparently four more; the first three are double. This last 
row is continued with a few weaker bristles, three in number. 
Length—1.57 mm. ‘Type in collection of the author. 
One $ from Lake Burford, N. M., off Peromyscus sp., col- 
lected May 25, 1918, by Alexander Wetmore. 
This species was taken in connection with large numbers of 
Ceratophyllus wagneri Baker, which appears to be an abundant 
parasite of this host. 
