Revieics — Annals of the South African Museum.. 423 



that a fourteenth edition has been called for. It treats in concise 

 and simple style of the properties and characters of niineralH, and 

 is suited to the needs of those who desire to acquire sufficient 

 knowledge to enable them to identify any specimen that may come 

 into their hands, and are not concerned with the more abstruse 

 questions underlying the phenomena of crystallisation. In the 

 present edition the discussion of the optical properties is based on 

 the ideas put forward by Mr. L. Fletcher in his " Optical Indicatrix," 

 and an excellent chapter on radio-active elements has been added by 

 Mr. E. H. Adye. The author completed the revision of the proof- 

 sheets only just before his lamented death in 1904. 



II. — Annals of thk South African Muskum. Vol. IV, Part 4: 

 The Trilobites of the Bokkeveld Beds. P.y Philip Lake, M.A., 

 F.G.S. 8vo; pp. 201-220, with 5 plates and 1 text-figure. 

 (West, Newman, & Co., London, 1904.) 



A S far back as 1856 J. W. Salter gave an account of the Trilobites 

 ]\_ of the Bokkeveld Beds as an appendix to Bain's paper "On 

 the Geology of South Africa" (Trans. Geol. Soc, ser. ii, vol. vii), 

 since which time but little has been added to our knowledge of 

 these South African forms. Dr. H. Woodward described (1873) 

 a remarkable species from the Cock's-comb Mountains (Q.J.G.S., 

 vol. xxix), and Dr. French (1897) figured a Homalonotus which he 

 believed to be new (Letha^a Geognostica, Th. i, Bd. ii, Lief. 1). 



The fine collection here described includes a number of new forms, 

 of which by far the most remarkable is the gigantic Homalonotus 

 colossus, sp. nov. 



The author has fortified his views as to the affinities of the species 

 he has described by examining the specimens in the British Museum 

 and in the Museum of the Geological Society of Loudon, which 

 contain Salter's types. 



The following species are recognized and described : — 



Phacops pupillHs, sp. nov. Dalmanites lunatus, sp. nov. 



Ph. arbuteus, sp. nov. Dalmanites sp. 



Ph. crinta-galli (H. Woodw.). Proctus malacus, sp. nov. 



Ph. Africantis, Salter. Ti/pihloniscus Baini, Salter. 



Ph. ocellus, sp. nov. Homalonotus Htrscheli, Miirch. 



Ph. impressus, sp. nov. H. quernus, sp. nov. 



Ph. {Uryphmus) differ, Salter. H. colossus, sp. nov. 



Phacops (?) sp. If. sp. 



The presence of a true Cri/plioeus and of spiny forms oi Homalonotus 

 indicates that the beds may be referred with certainty to the 

 Devonian, and probably to the lower division of that formation. 



Few of the forms have any very near allies in Europe. The 

 Phacopidfe are more closely allied to the forms described from 

 Brazil by J. M. Clarke and from Bolivia by A. Ulricb than to any 

 European ones. A. H. F. 



