70 



REPOET 108, U. S. DEPAETMEXT OF AGEICULTUEE. 



A tick has been described \inder the genus Ixodes as taken from a seal near AUiska; 

 but it has not been found again and its position is rather uncertain. 



Superfamily PARASITOIDEA. 



This superfamily includes three well-marked families, 

 two of which are known from but few species, and have 

 not\et been found in the United States. One of them, 

 the Spelseorhynchidae, connects the group to the Ixodoi- 

 dea and shows that the ticks should not be placed in 

 a group of sub ordinal rank. The families are distin- 

 guished on page 18. 



Family SPEL^ORHYHCHID^. 



Fig. ISd.—SpelaeorliyncMs praecursor. (After NeumaniL) 



Fig. 132.— Ceratixodes: Palpi of 

 male and female. (Original.) 



Under the name of Spelaeorhynchus praecursor (fig. 133) 

 Dr. Neumann has described a remarkable mite which he places as a subfamily of 

 the Ixodidae. This mite, which is less than 2 mm. long, was taken from a Brazilian 

 bat. Another species occurs on bats 

 in Panama. It differs from all ticks 

 in the presence of a sternal plate, 

 and therefore I agree with Oudemans 

 in placing it as a separate family, in- 

 termediate in some respects between 

 the Parasitidae and the Ixodidse, but 

 more related to the Parasitidae. The 

 dorsiun, as seen in figure 133, shows 

 a curious anterior piece or epistoma, 

 separated by a suture from the rest of the body. This is wholly unlike anything in 

 the Ixodidae, but more like the epistoma of certain Parasitidae. The palpi are simple, 



like those of Parasitidae, the mouth parts are 

 apparently retractile within a great buccal 

 cavity or camerostome, as in certain para- 

 eitids. But the shape of these mouth parts 

 is more like those of the Ixodidae. There 

 is a distinct median hypostome, unprovided 

 with teeth, and the mandibles are short, the 

 outer tip ending in two stout, curved pro- 

 cesses, similar to some ticks. The genital 

 aperture is near the anus, toward the tip of 

 the body, unlike either parasitids or ticks. 

 There are no ventral furrows. The tarsi are 

 furnished with a small caroncle as in the 

 parasitids. Excei)t its occurrence on the 

 bat, nothing is known of its life history. 



Family HOLOTHYRID.E. 



The species of Holothynis (fig. 134) are 

 moderately large mites occurring under 

 stones or among fallen leaves in New Guinea, 

 Ceylon, Seychelles, and Mauritius. The 

 body is wholly protected by a dorsal and 

 a ventral shield; the sj)iracles are situate 

 above the third pair of coxa*, just under the edge of the dorsal shield. The legj are 

 slender, sparsely hairy, and each ends in a pair of small claws; the palpi have the last 



Fig. U4.— Holothynis. (Original.) 



