Revieics — Professor Lewis^ Crystallography. 85 



species, three of which [S. ovata, S. Scotica, and S. suborbictdaris) 

 are described as new. In his observations on this genus the author 

 states that " Venus centralis, M'Coy, and Dolabra securiformis, 

 M'Coy . . . doubtless belong to the genus ; unfortunately, however, 

 the type specimen of the former has decomposed, and that name can 

 no longer be retained." If we are to conclude from this statement 

 that when the type-specimen decomposes the name of the species 

 disappears, what a prospect for the names of the Gault and London 

 Clay fossils, which have such a strong inclination to go 'wrong'! 

 The genus JEdmondia, De Koninck, is represented by about twenty 

 species, six of which are regarded as new, and the subgenus Scaldia, 

 De liyckholt, by two species. 



Of the Cypriuidse the author recognizes among the Carboniferous 

 Lamellibranchiata only the new genus Mijtilomoi-plia, the typical 

 Carboniferous form of which he considers to be that described by 

 Phillips as Cypricardia rhombea ; the only other British Carboni- 

 ferous species being M. angidata, n.sp. 



To the Crassitellidse Dr. Hind refers Hall's genus Cypricardella, 

 seven species of which are described in the present part ; Fischer and 

 Beushausen placed this genus in the Astartidse, and the author admits 

 that it really possesses characters intermediate between the two 

 "genera" [tau)ilies]. He regards Astartella and Cijpricardella as 

 probably identical, and says (p. 347) " the date of the description of 

 Astartella is 1858, the same year as that of Cypricardella," a state- 

 ment, however, which does not quite agree with the references to 

 these two genera given on the preceding page. 



4. A Monograph on the Inferior Oolite Ammonites of the British 

 Islands. By S. S. Buckman, F.G.S., etc. Part XI. Supple- 

 ment : ii. — Revision of, and addition to, the Hildoceratidae. 

 pp. xxxiii-lxiv ; pis. v-xiv. 

 Mr. Buckman continues his revision of this family, dealing chiefly 

 with the forms which were referred in the body of the work to 

 Lioceras and Ludwigia. He says that " nearly all the specimens 

 inscribed as Lioceras in the body of this work must be removed from 

 that position." The genus Lioceras is restricted, opalinua being the 

 type species of the genus, and " Quenstedt's fig. 10 in pi. vii of his 

 ' Cephalopoden ' is regarded as the arbiter of what is opalinus." 

 Several new species and not a few new genera are proposed. 



VI. — A Treatise on Crystallography. — By W. J. Lewis, pp. 612, 

 with 553 figures in the text. (Cambridge, 1899.) 



DURING Mr. Lewis's tenure of the University Professorship, 

 which has extended over nearly twenty years, the subject of 

 Mineralogy (in combination with Crystallography) has been made 

 an independent subject of the Natural Sciences Tripos, and for 

 some time has had a considerable number of students ; a textbook 

 of Crystallography at once suited to the requirements of the Tripos 

 and corresponding in its methods and terminology to the professorial 

 lectures will be a great boon to Cambridge men, and the book will 

 doubtless be welcomed in other Universities, both at home and 



