60 CURRENT LITERATURE. 



In all departments of palaeontology there is a tendency to multiply species on 

 very fine differences, and many of these in the present list might be wisely 

 reduced. Of 585 MS. names proposed by Mr. F. E. Edwards, "it is the 

 author's intention to describe and figure in due course, all these specimens." 

 There is a useful Bibliography, an Appendix by Mr. George F. Harris, F.G.S., 

 " On the Correllation Table of British with Continental Tertiary Strata," and 

 a short preface by Dr. Hy. Woodward. The list is carefully and well executed. 

 After each species is given the author's name, references to works in which there 

 are descriptions or figures, synonyms, and the horizon and locality where it occurs. 



On the whole Mr. Newton is to be congratulated on the completion of 

 a tedious undertaking well carried out. — W. E. C. 



Manual of Conchology by George W. Tryon, jun. Continuation by H. A. 



Pilsbry (ist Ser., pts., 53 and 54 ; 2nd Ser. pts. 29 and 30). Philadelphia : 



Academy of Natural Sciences. 

 Parts 53 and 54 of Series I. contain the commencement of the Polyplacophora. 

 Many new species, principally from Carpenter's MS. are described, though we 

 regret to notice that a large proportion are unfigured. The new species are : 

 Lepidopleurus granoliratus, Cptr. (near asellus), L. rugatus, Cptr. (near asellus), 

 I., curvatus, Cptr., Spongiochiton productus, Cptr., Chcetopleura gemmea, Cptr. 

 (somewhat like Tschnochiton mertensii), C. armillata, Cptr., Callochiton princeps, 

 Cptr., Stereochiton lobatus, Cptr. (has general aspect of Mopalia vespertitia), 

 Tschnochiton floridanus, Pilsbry (allied to /. limaciformis), I. fa/lax, Cptr., 

 /. acrior, Cptr., /. cariosus, Cptr., and /. conspicuus, Cptr. (all four near 

 I. magdalenensis), I. solid/**!-, Cptr., /. asperior, Cptr., I. peromatus, Cptr., 

 I. haddoni, Pilsbry, /. macgillivrayi, Cptr. (near /. oniscus), I. bisculptus, Cptr., 

 /. newcombi, Cptr. (near /. radians), I. radians (near /. inter stinctus), I. aure- 

 otinctus (near Tr. flexus), J. decipiens, Cptr., I. corrugatus, Cptr., /, cooperi, Cptr. , 

 (near mertensii), I. sinudentatus, Cptr. Comment on the arrangement of the 

 sections is best reserved until publication of the introduction, &c. In Series II., 

 pts. 29 and 30 continue and complete the Genus Cochloslyla. A commencement is 

 made with the supplement to the Helicidm, advancing as far as Mizrophysa. — 

 E.R.S. 



ANATOMY. 



The Asymmetry of Univalve Mollusca. (Journ. de Conch., pp. 117-208, 

 1892). 

 MM. Fisher and Bouvier have a long and admirable article on this subject. 

 They first enumerate the existing instances of sinistral mollusca, according as the 

 " sinistrosity " is ( 1 ) generic, (2) specific, (3) monstrous, cases in which the species 

 is indifferently dextral or sinistial being specially dealt with. The relations 

 between the position of the internal organs and the way in which the spire is 

 curled are then discussed. In all cases of " monstrosity," the position of the 

 organs is found to be reversed, the pulmonary aperture, e.g., if normally on the 

 right side, is then on the left. The same may be, and generally is, the case with 

 all normally sinistral species ; and of these, two large forms, Lanistes bolteniamts 

 and Chrysodomtts contraria are submitted, by the authors, to a detailed anatomical 

 examination. In some cases, however, e.g., sinistral Ampullarice, this displace- 

 ment of the organs does not take place, and it is shown that these, and similar 

 ''sinistral'' species are, in reality, " ultra-dextral," that is to say, the spire is 

 wound upside down, the apex being where the umbilicus should be, and vice 

 versa. Thus Planorbis is really sinistral, and apparently dextral scarlariform 

 monstrosities are only specimens in which the umbilical region has become 

 convex. The American genus Pompholyx, though apparently dextral, is really 

 ultra-sinistral, the pulmonary and genital orifices being on the left side. 



The general question of the asymmetry of Mollusca is then discussed, especially 

 with regard to its original causes. The authors incline decidedly towards the 

 views of Spengel and Biitschli on the primitive mollusc and its developments. In 

 crawling, as distinguished from swimming and burrowing mollusca, the growth of 

 a shell to shield the viscera produced a displacement of balance, and the shell 

 and the parts it covered fell over, in dextral species, to the left. Thus was 



