40 Brief Notices. 



interior near the Rhine — I came to several districts where neither 

 vine, olive, nor fruit-tree would grow, where they manured the 

 fields with 'marne' [candida fossicia creta~\, dug from the ground, 

 where they could get salt neither by digging nor from the sea, but 

 used instead of it salt charcoal made of the burning of certain 

 woods." 



3. Fossil Insects fkoji Ploeissant, Colorado. — This paper, 

 by Mr. T. D. A. Cockerell (Proc. United States Nat. Mus., vol. liii, 

 pp. 389-92, 1917), describes five new species of insects from the 

 well-known Miocene shales of Florissant, but being without figures 

 they are of little use to the palaeontologist. 



4. Minerals of Glamorgan. — Mr. F. J. North has issued a careful 

 paper on the Minerals of Glamorgan in the Trans. Cardi:ff Nat. Soc, 

 xlix, 1916. Some thirty species are recorded and fully described, 

 with notes and information of local interest. Special attention is 

 paid to economics, and the paper concludes with a bibliography. 

 Gold in rounded grains is recorded from the Keuper Marl. 



5. Tritylodon. — A recent examination of the skull of Tritylodon 

 loiigcevus, Owen, allows Dr. B. Petronievics to give as mammalian 

 characters: divided roots of molar teeth, multituberculate teeth, 

 straight and parallel rows of teeth, and no post-frontal bone ; as 

 reptilian characters: divided nares, pre-frontal bone, and frontal 

 bone not bounding the orbit ; while those characters both mam- 

 malian and reptilian are recorded thus : septomaxillary bones, 

 terminal position of anterior nares, backward position of posterior 

 nares, divergent parietals, orbito or alisphenoid (or orbitopalatine ?), 

 no postoi'bital bar, and brain-case antero-laterally closed. Some 

 further preparation of the type skull by Mr. Barlow has enabled 

 Dr. Petronievics to come to these conclusions, which he considers 

 show Tritylodon to be a direct evidence that the mammals have their 

 origin in reptiles, most probably in Theriodont Reptiles (Ann. Mag. 

 Nat. Hist. [8], xx, October. 1917). 



6. Folkestone Warren. — Despite the long literature on Folkestone 

 "Warren, it has been left to Mr. C. W. Osman (Proc. Geol. Assoc, 

 xxviii (2), 1917) to approacli the subject from a mechanical point of 

 view and elucidate its structure from the recurring landslips, 

 especially that of December, 1896. Studying the effect of com- 

 pression on the Gault, the critical slope of Chalk on Gault, types of 

 movements in the Warren, and the effect of water on those move- 

 ments, he describes the cross sections and accounts for the origin of 

 the Warren. Proceeding further, he measures up the Lower Chalk, 

 discusses the effect of the Ferques axis on deposition, and gives the 

 thickness of the Gault here and at various places in Kent. The paper 

 is illustrated by a large-scale section from Folkestone to Dover, and 

 sections at numerous points at right angles to the coast. A list of 

 fossils collected from the Chalk Marl is provided by Mr. H. A. Allen. 



