1882.] American Work on Recent Mollnsca in 1881. 881 



allotting one commissioner each to the eastern and western 

 shores. The report itself relates chiefly to vertebrate fisheries, 

 but the appendix is devoted entirely to invertebrates and further 

 " Oyster laws " are included in the compendium which closes the 

 volume. 



The appendix consists of (1) an Account of experiments in 

 oyster culture, by John A. Ryder ; (2) an Account of an experi- 

 ment in artificially fertilizing the ova of the European oyster, by 

 Master Francis Winslow, U.S.N, (referred to in this record for 

 1880); (3) a Bibliography of literature (38 entries) relating to , 

 oyster culture ; and (4) Notes on some of the early stages of 

 development of the clam or mananose {My a arenaria L.) by John 

 A. Ryder. 



The first paper contains an account of .the anatomy of the oys- 

 ter, with illustrative diagrams. Several points are developed 

 more fully than has been done by previous writers; the author's 

 attention is, however, chiefly directed toward the digestive, repro- 

 ductive and respiratory tracts, and the account does not claim to 

 be by any means complete. The pedal (?) muscles are not noted, 

 an omission characteristic of most papers on the oyster. It is 

 concluded that the oyster is dioecious. The " fat " of the oyster 

 is not fat at ail, but though containing some oil globules, is a 

 deposit of delicate protoplasm, easily digestible and nutritious, 

 which is almost wanting in breeding oysters, which are, therefore, 

 far less desirable as food. The food of the Chesapeake oyster is 

 discussed, and an instance is mentioned where a Pinnotheres 

 with eggs was- found 'established in the shell of an oyster upon 

 which again were attached numbers of Vibriones and Zootham- 

 nium colonies, whose increase, in all probability, formed part of 

 the food supply of the mollusk, so that host and -messmate were 

 mutually benefited. The fauna of the oyster beds is' enumerated, 

 with many notes on the various species mentioned. There are 

 but few mollusks, including the " soft-shell clam " (Mya) ; a spe- 

 cies of Modiola; Xylotrya fimbriate which rapidly destroys the 

 woodwork of hatching boxes, etc; Sotecurtus gibbus ; Crepidula 

 glauca; Litorina irrorata; Urosalpinx cinereus, the " drill " or oyster 

 borer ; and some small gaster.opods (probably in part Astyris and 

 Cerithiopsis), including some nudibranchiates. The artificial fertili- 

 zation of the ova is then treated of and is undoubtedly practica- 

 bl e, but the further preservation of the embryo oysters has so far 



