THE YEAR'S VERTEBRATE PALAEONTOLOGY 523 



(Proc. U.S. Nat. Mns., vol. xxxii. p. 271) as a subspecies of 

 the existing freshwater Gasterosteus williamsoni, whose range 

 extends from Alaska to California. The interest of the iden- 

 tification lies in the inference that the Lahontan beds are not 

 older than the Pleistocene. 



Pycnodont fishes from the Cretaceous of the Lebanon form 

 the subject of a paper by Mr. E. Henmy in the Centralblatt 

 fur Mincralogie (1907, p. 360) ; while Mr. Erich Heineke has 

 published in vol. viii. pt. 3 of Geol. und Pal. Abhaiidlungen a 

 detailed account of the ganoids and teleosteans of the Litho- 

 graphic Limestone of Nusplingen. 



Of Auiyzon brevipinne, a fish hitherto known only by a 

 single specimen from the (probably Oligocene) Amyzon beds 

 of British Columbia, Mr. L. M. Lambe has described, in the 

 Transactions of the Ro3 r al Society of Canada (vol. xii. p. 151), 

 a second and less incomplete example from the same horizon. 

 The palaeoniscid Myriolepis hibcrnica, from the Irish Coal 

 Measures, forms the subject of a note in the Annals and 

 Magazine of Natural History for December 1906 (ser. 7, 

 vol. xviii. p. 416). 



In the elasmobranch group Prof. E. Fraas (Neues Jahrb, 

 Mineral., 1907, vol. i. p. 1) gives further details of the structure 

 of the rostrum and dentition of Propristis schiveinfurthi, a saw- 

 fish from the Egyptian upper Eocene. In this fish the "saw," 

 which is slender and abruptly truncated at the tip, and attained 

 a length of rather more than two metres, has the same internal 

 structure as in Pristis, but carries teeth only in its terminal 

 fourth ; these teeth being short and broad-crowned, with sharp 

 fore-and-aft edges, which slightly overlap one another, thus 

 forming a sawing implement of great power and efficiency. 

 Of the well-known selachian genus Hybodus, Prof. E. Koken 

 gives further structural details in a memoir of considerable 

 morphological importance published in Geol. und Pal. Abhaiid- 

 lungen, vol. ix. pt. 4. 



The controversy as to the mutual relationships and general 

 affinities of the more primitive Palaeozoic fishes and fish-like 

 creatures is maintained with unabated vigour in several papers 

 by Dr. O. Jaekel and Dr. L. Dollo. The first group of 

 these papers, most of which were published in 1906 (although 

 they were not noticed in the article on the present subject in 

 last year's Science Progress), deal with the imperfectly known 



