880 American Work on Recent Mollusca in 1SS1. [November, 



In considering these views it should be borne in mind that the 

 gills (especially in Gasteropods) are almost purely epithelial struc- 

 tures, and therefore especially liable to modification; in most 

 cases they hardly exist in the embryonic stages. As regards the 

 correlation of inactivity with a high type of gill structure, it is per- 

 haps doubtful how far this will bear inspection. Yoldia is ex- 

 tremely active, but is almost like the sedentary Nucula in its gills; 

 Unio which has, according to Mitsukuri, highly specialized gills, 

 is, probably, in many cases nearly as active as Yoldia. Cardium 

 and Pecten are remarkable for their activity, and have highly de- 

 veloped gills, as also have Scintilla and Lepton, which move about 

 almost like Gasteropods. 



Whatever be the fate of incidental speculations of the author, 

 the paper is most suggestive and interesting, and may be taken 

 as an intimation of what is in store for malacology when the em- 

 bryologist and anatomists shall join forces and carry their investi- 

 gations from the young stages to the fully developed adult form 

 with greater continuity than appears to be the rule at present. 



Report of the Commissioners of Fisheries of Maryland, Jan., 

 1880 (8vo, pp. lxxviii, 1 1. unp., 269, 8; and 16 plates and sec- 

 tions), Annapolis, State printers, 1880. 



Report of T. B. Ferguson, a commissioner of fisheries [for the 

 western shore] of Maryland, Jan., 1881, 8vo, Hagerstown, Bell & 

 Co., 1 88 1 (pp. cxiv, 152, 6; and 18 plates besides cuts in the 

 text). 



The contents of the first report were alluded to by the recorder 

 in his summary for 1881, but not having been procurable by him 

 until a late date, exact references to its contents are now added. 

 The appendix contains the account of the " Development of the 

 American Oyster," by Dr. W. K. Brooks, which occupies pp. 

 I- 1 02, with ten plates; "Extracts from the Report of Master 

 Francis Winslow, U.S.N., made to C. P. Patterson, superintendent 

 coast and geodetic survey, of investigations of the oyster beds in 

 Tangier and Pocamoke sounds and parts of Chesapeake bay, 

 1878-9," comprising pp. 103-219, with four sections, and lastly, a 

 compend of the " Oyster laws," which, it is alleged by disinter- 

 ested parties, are never enforced except against non-residents, and 

 hence are practically a dead letter. 



The second report is made by Major Ferguson, on the Fish- 

 eries-work which came under his own supervision, the State law 



