Cooley & Kohls : Argasidaf. of N. America, etc. 



Coxae. — Coxae I and II a little separated, all others contiguous. 



Hood. — Indefinite. 



Camerostome. — Indefinite. 



Cheeks. — Large, about twice as long as wide, attached along one side, and 

 with a very few short hairs. 



Capitulum. — The capitulum is protrusile and when extended reaches 

 beyond the anterior end of the body. When so extended the basis capituli is 

 seen to be twice as long as wide and its length is about equal to the length of 

 the soft membrane ("neck") which unites the capitulum with the body. Living 

 specimens may show the capitulum either extended or withdrawn. Specimens 

 preserved in alcohol usually have the capitulum withdrawn and give little 

 evidence of extensibility. Basis capituli with the surface granulated as on the 

 legs, and faintly wrinkled. Numerous hairs present on the sides on the anterior 

 portion (not visible when the capitulum is withdrawn) . Palpal article 1 

 swollen and with its surface granulated. Tip of hypostome reaching to articu- 

 lation between articles 3 and 4. 



Hypostome. — With the sides subparallel, apex mildly notched. Denticles 

 small or faint; larger in the lateral files and progressively smaller toward the 

 median line. Length, female, 0.18 to 0.20; male, 0.16 to 0.17. 



Folds. — Coxal and supracoxal fold? present, the latter reaching to the 

 cheeks. 



Grooves. — Preanal, transverse postanal, and median postanal grooves 

 present. Dorso-ventral groove absent. 



Sexual opening. — At the level of the interval between coxae I and II. 



Eyes. — Absent. 



Anus. — Large, in an elliptical pattern. 



MALE 



i 

 The male differs from the female principally in the hypostome. The male 

 hypostome is smaller and has relatively smaller denticles. 



LARVA 



Large, sub oval. Length (including mouth parts), 1.20, width, 0.50. 

 Dorsal plate, oval. Legs long, slender. Capitulum terminal, large, its length 

 equal to about half the entire length of the larva. Basis capituli large, wider 

 behind, visible from above. Hypostome slender, long, pointed apically, and 

 on a conical base which is about as long as the hypostome. Denticles apically, 

 3 / ;J) , then 2 / 2 ; those of the lateral (marginal) files large, those of the median 

 files small. Length of hypostome, 0.24. 



This species is rather closely related to O. brodyi Matheson but may be 

 separated 'by the dentition of the adult hypostome and the character of the 

 mammillae. 



