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THE POPULAR SCIENCE MONTHLY. 



for it are, that it gives by contact indica- 

 tions of the volume of heat escaping by ra- 

 diation, and the velocity of loss ; also, that 

 by blowing on the bulb the degree of combus- 

 tion that takes place in the lungs is shown. 

 It is likewise serviceable as a means of de- 

 tecting the exact position of deep-seated 

 local trouble, giving valuable indications 

 where the thermometer fails. 



A New Fossil Crastacean. A new crus- 

 tacean species, allied to Eurypterus and 

 Pleroffotus, has been described by A. R. 

 Grote and W. H. Pitt, under the name of 

 Eusarcus scorpionis. The specimen was 

 fouTid in the water-lime group at Buffalo, 

 N. Y. Its length is 250 millimetres, and its 

 greatest width 110 millimetres. The ceph- 

 alo-thoracic portion appears to be sepa- 

 rate from the body ; the legs are in the 

 same number as in Eurypterus ; the swim- 

 ming-feet appear to differ by the straighter, 

 less rounded outer margins ; the spines of 

 the anterior feet appear to be long, curved, 

 and to have an anterior direction. The ab- 

 sence of chelate appendages to the posterior 

 margin of the feet is particularly notice- 

 able. The first seven broad segments of 

 the abdomen form a large ellipse. There 

 is an evident and remarkable narrowing of 

 the succeeding caudal segments. The in- 

 terest which attaches to this remarkable 

 crustacean arises from the discovery of a 

 form which may be allowed to be higher 

 tliau Eurypterus and Pterogotus. 



Reptilian Affiuities of Birds. Prof. E. 

 S. Morse has for a long time made a study 

 of the bones of embryo birds. At this 

 year's meeting of the American Association 

 he recalled briefly the evidence he had 

 shown last year regarding the existence of 

 the intermedium in birds, by citing the 

 embryo tern, in which he had distinctly 

 found it. This year he had made a visit to 

 Grand Menan, expressly to study the em- 

 bryology of the lower birds, and was fortu- 

 nate in finding the occurrence of this bone 

 in the petrel, sea-pigeon, and eider-duck. 

 This additional evidence showed beyond 

 question the existence of four tarsal bones 

 in birds as well as four carpal ones. In 

 these investigations he had also discov- 

 ered embryo claws on two of the fingers 



of the wing the index and middle finger. 

 Heretofore in the adult bird a single claw 

 only had occurred in a few species, such as 

 the Syrian blackbird, spur-winged goose, 

 knob-winged dove, jacana, mound-bird, and 

 a few others ; and in these cases it occurred 

 either on the index or middle finger, or on 

 the radial side of the metacarpus. All these 

 facts lent additional proofs of the reptilian 

 affinities of birds. 



American Pedigree of the Camel. 



Though the evolutional pedigree of the 

 horse may be distinctly traced in the suc- 

 cession of equine genera whose remains are 

 found in the Tertiary strata of our Western 

 Territories, nevertheless, the horse, as he 

 at present exists, is not indigenous to this 

 continent, but has been imported from Eu- 

 rope. The pedigree of the camel may also 

 be constructed from materials supplied by 

 American paleontology. Prof. Cope has re- 

 cently unearthed a number of genera which 

 must be regarded as the ancestors of the 

 camel. And it is worthy of note that, al- 

 though the more prominent genera of the 

 series which resulted in the horse, for in- 

 stance Anthitkermrn and Hippotherium, have 

 been found in European formations, no well- 

 determined form of the ancestral series of 

 the camel has up to the present time been 

 found in any formation of the Palgearctic 

 region. " Until such are discovered," says 

 Prof. Cope, " there will be much ground for 

 supposing that the camels of the Old World 

 were derived from American ancestors." 



Arctic Meteoroloary. During Weyprecht 

 and Payer's expedition to the north-polar 

 regions the air in winter seemed always to 

 contain particles of ice. This was seen not 

 only by parhelia and paraselene when the 

 sky was clear, but also in astronomical ob- 

 servations. The images of celestial objects 

 were hardly ever as clear and well defined 

 as at lower latitudes, although the actual 

 moisture in the atmosphere was far less 

 than is usual in temperate climes. It hap- 

 pened very often that, with a perfectly clear 

 sky, needles of ice were deposited in great 

 quantities upon all objects. It was impos- 

 sible to determine the quantity of atmos- 

 pheric deposits, as during the snow-storma 

 no distinction could be made between the 



