32 NORTH AMERICAN ANOPLURA 



angle. Second to fifth segments with pleural plates which are nearly 

 square and have the posterior angles produced into a short tooth. First 

 with one very short hair, remainder without hairs. 



On the ventral side, segment one with median group of tw r o hairs; 

 two to six with four ; seven with two widely separated ; all the segments 

 except the first, eighth and ninth with a hair near the lateral margin. 

 Genital plate with a transverse row of five or six small spines. Gonapods 

 with two or three long hairs ; ninth segment with two short, stout spines 

 near the posterior margin. 



FAHRENHOLZIA n. gen. 



We are establishing this genus for a single species taken from a 

 pocket rat, Dipodomys calif or nicus (family Heteromyidae). The species 

 is of interest not only as the type of a new genus, but as the first Ano- 

 pluran to be recorded from any of this small and very peculiar family of 

 rodents. The genus stands between Haemodipsus and Enderleinellus, 

 having the middle and posterior pairs of legs of the same size, as in Hae- 

 modipsus, and having a projection on the anterior margin of the hind 

 tarsi as in Enderleinellus. The second sternite bears a uair of chitinous 

 plates of doubtful homology, which are perhaps the homologues of cer- 

 tain similar but much smaller plates on the third sternite in Enderleinel- 

 lus. It is possible that these plates represent the pleurites of the first 

 segment. 



Diagnosis of the Genus. — Antennae five- jointed, similar in male 

 and female. Eyes lacking. Anterior pair of legs small, with slender 

 claws ; middle and posterior pairs much larger, and with broad claws. 

 Posterior tarsi with a short projection on the anterior margin. Abdomen 

 without chitinized tergal and sternal plates. Pleural plates well defined, 

 present on the second to fourth segments. Sternite of the second seg- 

 ment with a pair of chitinous plates, which may represent the pleurites 

 of the first segment. Each segment with a single transverse row of 

 spines. Named in honor of H. Fahrenholz, whose excellent papers upon 

 the Anoplura have been of much assistance to us. 



Fahrenholzia pinnata n. sp. 

 Plate III, fig. 2 ; plate V, figs. 5 and 6; plate VI, fig. 10; text fig. 13. 



Numerous males and females from several individuals of Dipodomys 

 calif ornicus (pocket rat) all taken at Covelo, Calif. 



