36 IXODOIDEA, OR TICKS, OF THE UNITED STATES. 



Type. — M. unnthemi Karsch. 



The replacement of the familiar Boophilus by this almost unknown 

 name is a case where the inflexible application of the law of priority 

 is greatly to be deplored, especially since there is no resulting benefit 

 whatever to science. 



But one species has as yet been found in tlie United States, but an 

 allied form is known from the West Indies, and will, perhaps, some 

 day occur in our country. 



Margaropus annulatus Say. 



Male. — Small, brownish yellow, legs paler, no markings. Capitu- 

 lum (PL X, fig. 8) rather crescentic, acute on lateral angles, hind 

 angles prolonged into short spines; palpi extremely short, shorter 

 than the hypostome, the joints with transverse acute ridges. Dor- 

 sum one and one-half times longer than broad, broadest near hind 

 end, surface usually indicating two furrows in front, sublateral, and 

 three furrows behind, with many rather small subequal punctures; 

 festoons indistinct, but usually nine of them indicated. Legs slender, 

 the first pair short, fourth pair much larger than the others; tarsi 

 (PI. V, fig. 7) short; all with scattered hairs. Coxse I (PL V, fig. 5) 

 with two spines behind, the inner one very short, the outer one more 

 slender and sometimes very long, and in front a long spine-like pro- 

 cess; other coxse mutic. Two prominent long adanal plates, and 

 each side a smaller, shorter, curved plate ; the tips of these four plates 

 are seen, in a dorsal view of the tick, projecting behind the posterior 

 margin. Stigmal plate small, subelliptical, with about twenty-five 

 or thirty large granules and many smaller ones. 



Length of female, 2.2 mm. 



Female. — Shield red-brown, often very dark, abdomen brighter red- 

 brown; legs pale; no markings. Capitulum (PL V, fig. 6; PL X, fig. 

 7) broad, hind angles barely distinct, lateral angles acute; palpi ex- 

 tremely short, much shorter than the hypostome, and with ridges, as 

 in male; porose areas elliptical, widely separated, and pointing out- 

 ward. Shield (PL V, fig. 6) plainly longer than broad, broadest at 

 eyes, quite suddenly narrowed behind the eyes; surface wrinkled, but 

 the middle of front is smooth; a few punctures, mostly lost in the 

 wrinkles. Abdomen with fine hairs; legs small and slender, hairy; 

 coxse unarmed; stigmal plate (PL V, fig. 7) small, only a little longer 

 than broad, with a number of scattered visible granules, and many 

 very minute ones. 



Length of female shield, 1.1 mm. 



Specimens may be taken from cattle in many parts of the country, 

 but are native only to the Southern States, where they occur on deer 

 and other animals. This is "the cattle tick" and the proven dis- 



