DESCRIPTIONS AND DETERMINATIONS OF SPECIES 



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bit (Panama Canal Zone). Osborn records it from a prairie hare, Lepus 

 campestris (Ames, Iowa), and from an unnamed host (Baltimore, Md.). 

 Through the kindness of Mr. Cummings we have been enabled to com- 

 pare our specimens with a co-type of H. ventricosus, and are certain of 

 our identification. The published descriptions of the species are rather 

 unsatisfactory, and we are therefore re-describing it somewhat more fully. 

 Description of the Female. — Total length 1.5 mm., length of head 

 .35 mm., length of abdomen 1.05 mm., width of thorax .28 mm., width of 

 head .3 mm., width of abdomen .72 mm. 



Fig. 



-Haemodipsas ventricosus (Denny) ; pleural plate and ventral side of 

 terminal abdominal segments of female. 



Head with very convex anterior margin, widening slightly behind 

 the antennae, the temporal margins convex and with an abrupt angle 

 posteriorly; occiput rather narrow and quite convex. Anterior margin 

 and forehead with several small hairs ; a very faint transverse suture im- 

 mediately behind the antennae with four small hairs arranged along it, 

 four or five short spines along the temporal margin, and a single long 

 hair at the posterior-lateral angle. Antennae set slightly in advance of 

 the center of the head ; first segment not conspicuously enlarged, about 

 as wide as long ; second segment of about the same length but more slen- 

 der; third, fourth and fifth segments sub-equal. 



Thorax relatively small, much narrower than the head and about 

 twice as wide as long, widest posteriorly, apparently composed entirely of 

 the prothorax. Anterior margin with a very deep and narrow V-shaped 

 notch which reaches nearly to the posterior margin. A single short spine 

 at each anterior angle, and a short spine and a long hair at each posterior 



