MAKGAROPUS ANNULATUS SAY. 37 



seminator of southern cattle or splenetic fever. Much has been writ- 

 ten upon it, and its life history is fairly well known. 



It Avas described by Say from deer from Florida; described by 

 Koch, and later by Packard, and by Riley as Ixodes hovis. Under 

 this name it was long known, until Curtice proposed for it the genus 

 Boophilus. Neumann has recently shown that the type of Margaro- 

 pus is a true Boophilus^ therefore it is necessary to drop the familiar 

 cognomen, under which it had become of prime economic importance. 

 Neumann at first considered M. annulatus to be of world-wide distri- 

 bution ; but in 1899 Fuller separated the South African and the Aus- 

 tralian forms, and now it is believed that M. annulatus occurs only 

 in North America. 



Biological and economic accounts of this species can be found in 

 Bulletin No. 72 of this Bureau. This tick is rarely recorded from 

 an}^ animal other than cattle; however, Mr. J. D. Mitchell has found 

 it on sheep, and I have seen specimens taken from ponies in Michigan. 



Genus AMBLYOMMA Koch. 



Venter with a distinct curved groove behind the anus and a more or 

 less distinct median furrow behind. Capitulum rather small ; porose 

 areas longitudinal. Palpi long and slender, second joint about twice 

 as long as broad, third very much shorter than the second. Shield 

 usually with some markings; ocelli present, and on margin of the 

 shield. Abdomen showing festoons behind (except in distended 

 female). Coxa I with one or two teeth behind; coxa IV of male not 

 enlarged, usually with a spine behind. No anal plates in male. 

 Stigmal plate subtriangular or elongate. Tarsi II, III, and IV 

 plainly divided, the basal part much shorter than the apical part, and 

 a distinct tooth-like claw at apex. 



Type. — A. cajetiiietise Fabricius. 



Table of the Species. 



1. I'oxa I with but one spine, metatarsi (except I) with two thickened 



spurs at tips; second joint of palpus not twice as long as third; porose 



areas elongate; shield brown, with silvery marks maculatnm. 



Coxa I with two spines; metatarsi without stout spurs at tips, only slen- 

 der hairs 2 



2. Projections of coxa I blunt and short; porose areas elongate; second 



joint of palpus not twice as long as third ; coxa IV of male with only 



a tubercle behind; large species titbcrculatum. 



Projections of coxa I longer, and at least one of them sharp-pointed ; 

 second joint of palpus twice as long as third ; coxa IV of male with a 

 long spine; smaller species 3 



3. Porose areas nearly circular ; shield of both sexes pale yellowish, with 



some silverj' streaks and marks, and some reddish spots; shield of 



female as broad as long cajennense. 



Porose areas elongate; shield brown, in female with an apical silvery 

 mark, hi male with two small apical and two or four other silvery 

 spots; shield of female longer than broad amcricanum. 



