60 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVIII. 



Fig. 108.— M achocheles 

 cakolixensis; venter c)f 



FEMALE. 



stiiuo liaving heon passed in the iiiotluM". The :il)domen is practically 

 wantiiio- in the male, and in the female it is ex- 

 tremely small. The short, thick, bristly legs are 

 set at aliout equal distances around the body. 

 Although the stigmata are on the dorsum, the 

 peritreme extends down over the sides and upon 

 the venter. Doctor 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. 

 One species has l)een described from our country. 

 The allied genus /V 

 /vV///.sy7/ /v/.v differs 

 in having the dor- 

 sal shield divided, and the peritreme does 

 not extend down on the venter. The 

 female has a wrinkled fan-shaped expan- 

 sion to tip of l)ody, b}- which she retains 

 hold of the skin of the bat. Kolenati de- 

 scribed several allied genera, but most, if 

 not all of them, are stages of Pttropiax. 

 The genus yY//r>//y.s-.s?6s- differs in having 

 a large abdomen, separated by a constric- 

 tion from the cephalothorax; it occurs on sparrows. The species of 



L!poin/ssiis are parasitic on mice and 

 similar mammals. They are pale- 

 colored, but otherwise much like 

 Derma II yf<.si(s. The latter genus oc- 

 curs on l)irds. especially those kept 

 in domestication. D. (jalUnm is a 

 serious pest of poultry in many 

 parts of the country. They hide 

 in cracks and crevices by day, but 

 at night crowd upon the fowls and 

 suck their })lood. They are more 

 injurious in the Southern States 

 than elsewhere. Sometimes they 

 attack man and cause itching and 

 soreness. Chickens endeavor to get 

 rid of the mites by a dust-l)ath, 

 but when the mites are numer- 

 ous, it will be best to spray or 

 wash the hen-house with kerosene, benzine, or gasoline. Whitewash- 

 injj- with carbolated lime will destroy a great many of them. If the 



lOy.— MAfROCHELES SPIN ATI'S; 

 LEGS II AND IV OF MALE. 



Fig. 110.— Me(;isthanus floridanus. 



