Moll 1 
VII. MOLLUSCA. 
BY 
E. R. Sykes, B.A., F.L.S. 
Assisted by E. A. Smith, F.Z.S., and G. C. Crick, F.G.S. 
CONTENTS. 
Introduction. 
Page 
1 
I. Titles . 
. 3 
II. Biology. 
Anatomy, Physiology, &c. 
. 34 
Distribution. 
Geographical. 
Non-Marine. . . . 
. 38 
Marine. 
. 45 
Geological. 
. 49 
III. Systematic. 
Cephalopoda. 
. 55 
Dibranchiata .... 
55 
Ammon ea. 
. 55 
Tetrabranchiata . . . 
. 59 
Gastropoda. 
. 60 
Pulmonata. 
. 60 
Stylommatophora. . 
. 60 
Basommatophora. . 
. 70 
Page 
Opisthobranchiata ... 70 
Nuclibranchiata . . . 70 
Tectibranchiata . . . 71 
Nucleobranchiata . . . 71 
Prosobranchiata . . . . 71 
Pectinibranchiata... 71 
Scutibranchiata ... 80 
Scaphopoda.81 
Pelecypoda.82 
Septibranchiata .... 82 
Eulamellibranchiata . . 82 
Pseudolamellibranchiata . 85 
Filibranchiata.86 
Protobranchiata .... 86 
Amphineura.87 
Aplacophora.87 
Polyplacophora .... 87 
INTRODUCTION. 
The most salient feature of the literature of the year 1899, bearing on the 
Mollusca, appears to be a general increase in the number of papers dealing 
with every branch. 
Amongst the works relating to the general subject special attention may 
be directed to the new part of Cossmann’s (92) ‘ Essais de Paleocon- 
chologie,’ in which he deals with portions of the Toxoglossa and Bachi- 
glossa; though written from the paleontologist’s point of view, it is of 
considerable importance to students of the recent Mollusca. In a similar 
category may be placed the American edition of Zittel’s (595) well-known 
