12 NATURAL SCIENCE. Jan. 



published. It is a good example of the varying " form " displayed by 

 a scientific author, his present effort being as successful as his 

 Anatoviie Comparcc was the reverse. 



It is interesting to remark how the skeletons of animals that we 

 have always hitherto regarded as typically Old World forms of life 

 are still being discovered in the Tertiary formations of North 

 America. The latest announcement is that of the discovery of a 

 hyaena by Professor Cope in the Pliocene formation of Texas. It is 

 an animal about as large as the common spotted hyaena, and is only 

 known to differ from //)v?««-proper in the possession of a fourth pre- 

 molar in the lower jaw. It is named Bovophagns diversidens (American 

 Naturalist, 1892, p. 1028). With the hyaena were also found two tortoises, 

 one bird, one sloth, three mastodons, one peccary, three horses, one 

 camel, a weasel, and a large cat. One of the horses— a true Equus — 

 is remarkable for its small size, the teeth being no larger than those 

 of a sheep. 



Sir Herbert Maxwell and Mr. J. E. Harting, the Chairman 

 and Secretary respectively of the Committee appointed by the 

 Board of Agriculture to investigate the plague of field voles in 

 Scotland, will shortly proceed to Thessaly to examine the results of 

 Professor Loeffler's work in that region. As is well-known, the Pro- 

 fessor has attempted to exterminate the Thessalian voles by placing 

 in their food the germs of mouse typhus, and he claims to have been 

 successful. 



The important monograph on the development of the macrurous 

 Crustacea, by Professor W. K. Brooks and Mr. F. H. Herrick, to 

 which we referred some time ago (vol. i., p. 243), has lately been 

 issued in vol. v. of the Memoirs of the National Academy of Sciences. 

 The other memoirs in the same volume relate to physical subjects. 



We have received from Mr. Hugh Fulton a photograph of the 

 beautiful little land-shell, Opisthostonm mirabile, discovered a short time 

 ago by Mr. A. H. Everett in North Borneo. In ornamentation this 

 minute species rivals the 0. grandispinosa, and several specimens have 

 lately been obtained by Mr. Fulton. 



In the recently-issued number of the Annals of Botany, Dr. 

 Schunck gives a short account of the work done on the chemistry 

 of the green colouring matter of plants (chlorophyll) since the publi- 

 cation of his former paper on the subject in the volume for 1889. — 

 In the same journal Mr. R. A. Rolfe describes a natural liybrid 



