Cooley & Kohls : Argasidae of N. America, etc. 97 



posteriorly and becor.-.es an arc of a circle, the radial center of which would 

 be the insertion of leg IV. The top of this arc is smooth while the surface of 

 all other ridges is irregular. In living specimens leg IV in its movements is in 

 contact with the smooth ridge, which is enough elevated to protect the spiracle 

 placed just below it. Leg IV comes in contact with this smooth arc at about 

 the trochanter. 



While in most Argasidae the spiracle is usually placed between coxae III 

 and IV, in this species it is situated well back of coxa IV. 



Grooves. — Only the deep, short, transverse postanal groove is present. 



Sexual opening. — Placed at about the level of the posterior ends of coxae 

 I. V-shaped depression, including the opening, present in the female, absent 

 in the male. 



Eyes. — Absent. 



Anus. — Small, in an oval pattern, distant from the transverse postanal 

 groove. 



In this species the nymphs are remarkable in having a V-shaped depres- 

 sion in the position where the sexual opening is to appear, making it singular- 

 ly difficult to distinguish between nymphs and adults. The original descriptions 

 included both adults and nymphs, the authors believing that they had both 

 before them. Dr. Mazziotti has recently sent us a male and a female specimen, 

 the male being the first one we have seen. These specimens show the different 

 male and female sex opening quite clearly and make it evident that the speci- 

 mens before us at the time the species was described were nymphs. The V- 

 shaped depression is lacking in the male, while it is present, as in the nymph, 

 in the female. 



The above description is made from three large females from Mr. Flock 

 (17189) and a male and female from Dr. Mazziotti. They differ from the 

 nymphs in having the continuous submarginal ridge less elevated, the dorsal 

 and ventral surfaces smoother and in having more spur ridges in the pattern 

 of the folds on the venter. The smallest nymphs we have seen are shorter in 

 proportion to the width than in adults and measure 1 .98 x 1.11. 



This remarkable tick is easily separated from other known species by its 

 elongated body, the parallel marginal ridges, and the pattern of ridges on the 

 venter as well as by other characters. 



HOSTS 



While this species has never been actually taken from bats, it has been 

 found only on bat guano or on the walls of bat caverns. 



DISTRIBUTION 



Arizona. — 16083, from bat guano from mine tunnel, November 3, 1939, 

 Picacho Peak, near Picacho, 28 nymphs; 17863, from bat guano and rock 

 crevices in mine tunnel, May 23, 1940, Picacho Peak, near Picacho, several 

 nymphs; 17875, rock crevices in mine tunnel, May 28, 1940, Las Guijas, 1 



