80 Miscellaneous. 



mandibles end in pincers or cheloe, resembling lobster-claws ; the 

 movable joint of the chelas has two teeth at the end ; the opposed 

 extremity of the fixed joint of the chelae is narrow, and ends in a 

 hook. 



Dr. Turnbull had seen the cattle killed, and was positive that the 

 mites occupied the position in the ear of the steers while these were 

 alive ; such being the case, the Acarus may be viewed as a parasite 

 of the ox, and may be specifically named Gamasus aurls. — Proc. Acnd. 

 Nat. Sci. Philad. 1872. 



The Horns of Antilocapra. By Dr. J. E. Gray, F.R.S. &c. 



The British Museum has purchased of Mr. E. Gerrard, junior, the 

 skin of an adult male Antilocapva which was just developing the 

 new horny sheath ; and this was rather diiferent from what, by ob- 

 serving the horns in a more developed state, I had been led to 

 expect. 



The core of the horns was covered with a thick skin, which in the 

 dried state is black ; but the apex is covered with a small conical 

 sheath about 1| in. long and ^ in. Avide at the base, hard and per- 

 fectly horny, very like the horn of cattle. It is black, with a white 

 acute tip about | in. long. 



The horny sheath of a more developed specimen brought at the 

 same time has a similar hard horny tip; but the lower part of the 

 hoi-n is less solid and more evidently formed of felted, matted hair, 

 which is more distinct and less compactly matted at its base or last 

 developed part ; so that it would appear that the skin of the core 

 first develops the horny tip, and then the more spongy part formed 

 of felted hair. 



Notice of a new and remarkable Fossil Bird. By 0. C. Marsh. 



One of the most interesting of recent discoveries in paliEontology 

 is the skeleton of a fossil bird, found during the past summer, in the 

 upper Cretaceous shale of Kansas, by Prof. B. F. Mudge, who has 

 kindly sent the specimen to me for examination. The remains in- 

 dicate an aquatic bird about as large as a pigeon, and differing 

 widely from all known birds in having biconcave vertehrce. The cer- 

 vical, dorsal, and caudal vertebras preserved all show this character, 

 the ends of the centra resembling those of Fhsiosaurus. The rest 

 of the skeleton presents no marked deviation from the ordinary avian 

 type. The wings were large in proportion to the posterior extremi- 

 ties. The humerus is 58-6 milUms. in length, and has the radial 

 crest strongly developed. The femur is small, and has the proximal 

 end compressed transversely. The tibia is slender and 44-5 miUims. 

 long ; its distal end is incurved as in swimming birds, but has no 

 supratendinal bridge. This species may be called Ichth>/ornis dispar. 

 A more complete description will appear in an early number of 

 Silliman's Journal. 



Yale College, Sept. 26th, 1872. 



