306 



SCIENCE. 



[N. S. Vol. XII. No. 295. 



Phytogeny of the Rhinoceroses of Europe : 



By Henry F. Osborn, American Museum 



Natural History, New York City. 



This paper will be printed in the Bulletin 

 of the American Museum of Natural His- 

 tory. 



Difficulties in a systematic arrangement 

 of Rhinoceroses resulting from recent dis- 

 coveries. 



Necessity of phylogenetic classification. 



Great antiquity of separate phyla. 



Our ignorance of the stem form. 



Revision of the family Ehinocerotidse 

 into seven subfamilies representing differ- 

 ent phyla. 



Theory of migration from Africa. 



On the Inflection of the Angle of the Jaw in the 

 Marsupialia and other Mammals: By B. 

 Arthur Bensley, Columbia Univer- 

 sity, New York City. To be printed 

 in Science. 



On a Phytogeny of the Marsupialia: By B. 

 Arthur Bensley, Columbia University, 

 New York City . (Abstract withdrawn . ) 



On the Composition of the Monotreme Skull : 

 By B. Arthur Bensley, Columbia Uni- 

 versity, New York City. (By title.) 



Lymphosporidium truttce, nov. gen. nov. sp. 

 The Cause of a Recent Epidemic among 

 Brook Trout : By Gary N. Calkins, Co- 

 lumbia University, New York City. 

 In October, 1899, my attention was called 

 to a disastrous epidemic among the brook 

 trout (Salvelinus fontinalis') in a Long Is- 

 land Hatchery. Investigation showed the 

 cause of the trouble to be a new genus 

 which I have placed provisionally with the 

 Serumsporidia (L. Pfeffer) among the Spor- 

 ozoa, a class of parasitic Protozoa. 



The spores of the parasites accumulate 

 in the lymph spaces of the fish and prevent 

 normal nourishment of the tissues. This 

 leads ultimately to ulcers of various shapes 

 and sizes. 



The spores give rise to 8 sporozoites or 

 germs each of which develop into an adult 

 amcBboid individual about 25 mu. (.001 

 inch) in length. This penetrates the bundles 

 of unstriped muscle cells of the digestive 

 tract and becomes mature. At maturity a 

 spore-forming cyst is developed in the 

 lymph and the spores are carried through- 

 out the entire animal. 



The epidemic which lasted from May 

 until December, 1899, killed off all the 

 fish in the hatchery. The origin, preven- 

 tive measures and remedies were not dis- 

 covered. 



The Primitive and Secondary Types of Verte- 

 brate Embryos : By Professor Charles S. 

 MiNOT, Harvard Medical School, Boston, 

 Mass. 



This paper gives a comparison of the 

 development in marsipo-branchs, ganoids, 

 dipnoans and amphibians as representing 

 the primitive type of vertebrate develop- 

 ment. The Selachian, Teleost, Sauropsidan 

 and mammalian types are regarded as 

 secondary modifications. It also includes 

 a comparative study of the form of the 

 embryo in the Ichthyopside and Am- 

 niota. 



A Partial Phylogeny of the Genus Cancer. 



By A. S. Packard, Brown University. 



A comparison of the miocene tertiary 

 species of cancer {Cancer Proavitus Pack.) 

 with the two species now living in the 

 waters of Vineyard Sound, brings out the 

 interesting fact that the extinct species is 

 the stem or ancestral form from which the 

 recent species have apparently descended. 



Cancer Proavitus presents characters in 

 which it resembles C. borealis as well as C. 

 irroratus. It resembles C. borealis in the 

 higher, more pointed granulations on the 

 postero-lateral margin of the carapace, and 

 in the quite high and sharp spines on the 

 ridges of the hand as well as the numerous 

 setiferous spines and hairs; on the other 



