76 



EEPOET 108, U. S. DEPARTMENT OF AGEICULTUEE. 



First pair of legs at one side of the mouth opening; dorsal surface of body 

 does not project in front of the camerostome; male genital opening 

 usually on the anterior margin of the sternal plate (sometimes in the 



middle) 4 



4. Jaws of mandibles vdthout teeth, often stylate or needlelike; parasitic on 

 birds, mammals, or reptiles; tarsus I with claws or caroncles; leg II of 

 male never with processes; anus in female usually at the front end of 

 the anal shield; all the chitinous shields rather weak, and often not 

 evident DERMAXYssixiE. 



Jaws of mandibles toothed; rarely stylate or needle-like; usually not found 



on animals, except insects \ Parasitix^. 



The Spinturnicinse are chiefly parasitic on 

 bats. There are many species of Spintumix ^ 

 (Pteroptus), several already described from 

 the United States; the other genera have but 

 few species. The group is remarkable on 

 account of the young hatching with the full 

 complement of legs, the larval stage having 

 been passed in the mother. Although the 

 stigmata are on the dorsum, the peritreme 

 often extends down on the sides. 



The principal genera may be separated as 

 follows: 



1. Coxae I contiguous over the rostrum; 

 but one dorsal shield; stigmata 

 without peritreme Sternostomum. 



Coxae I separated by rostrum; usually 

 a distinct peritreme 2 



2. Abdomen constricted behind hind 

 coxae; peritreme very short; a sin- 

 gle dorsal shield. Ptilonyssus. 



Abdomen not constricted or barely 



so; peritreme quite long 3 



3. "With two dorsal shields Periglischrus. 



With but one dorsal shield Spintumix. 



Spintumix (figs. 137, 138), formerly called 

 Pteroptus, is parasitic on bats. " It is remark- 

 able on account of its curious shape and 

 dorsal position of the stigmata, and also on account of the young hatching with 

 the full complement of legs, the larval stage having been passed in the mother. 

 The abdomen is practically wanting in the male, and in the female it is extremely 

 small. The short, thick, bristly legs are set at about equal distances around the 

 body. Although the stigmata are on the dorsum the peritreme extends down 

 over the sides and upon the venter. Dr. Oudemans has described an accessory 

 nymphal stage in one species of this genus. It occasionally issues from the second 

 nymphal stage and differs particularly in the nature of the vestiture; its use is 

 unknown. Several species have been described from this country. Apparently the>- 

 do not seriously inconvenience the host, for nearly every bat examined harbors a 

 few specimens. 



The genus Periglischrus (fig. 139), which occurs on foreign bats, is similar to Spin- 

 tumix, but has the anterior coxae separated, two approximated dorsal shields, and the 

 female has a genital shield. The stigma and its peritreme are on the dorsum, the 

 latter quite long and extending parallel to the margin of the shields. The legs are 

 heavy and densely bristly as in Spintumix. The female has a wrinkled, fan-shaped 



1 Cclcripcff Montafru. used by some for this genus, was not described in 1808, but only 

 mentioned ; so it is a nomen nudcm. 



Fig. lio.—Dcrmanyssus gallinac 

 •illustration.) 



(Author's 



