tendency of sediment support a pseudo-feces growth retardation hypothesis, 

 i.e., slower growth in finer sediment because rate of expulsion of pseudo- 

 feces is increased. - modified author's abstract - J.L.M. 



2151 



Jones, C. C. 1979. 



Anatomy of Chione cancellata and some other Chionines, Bivalvia: Veneridae. 

 Malacologia 1: 157-199. 



Important information on Mercenaria mercenaria thought unlikely. Did not 

 search beyond SUNY-Stony Brook library. - J.L.M. 



2152 



Keck, Richard T., Robert C. Heess, John Wehmiller, and Don Maurer. 1978. 



Sublethal effects of the water-soluble fraction of Nigerian crude oil on 

 the juvenile hard clams, Mercenaria mercenaria (Linne) . Environ. Pollut. 

 15(2) : 109-119. 



Juvenile Mercenaria mercenaria were exposed to the water-soluble fraction 

 of Nigerian crude oil at concentrations ranging from 7 ppm to 0.06 ppm. 

 During the six-week experimental period the feeding rates of clams exposed 

 to hydrocarbons were significantly lower than those of controls. Growth 

 rates of control clams were three times as great than growth rates of exper- 

 imental groups. Mortalities were low during the entire experimental period, 

 but during a two-week depuration period all clams in the most polluted con- 

 dition (7 ppm) died. - modified authors' abstract - J.L.M. 



2153 



Keith, M. L.,and E. T. Degens . 1959. 



Geochemical indicators of marine and fresh-water sediments. In Researches 

 in Geochemistry. Philip H. 7Abelson (ed.) , John Wiley & Sons, Inc., New 

 York: 38-61. 



Marine fossils measured include Venus mercenaria, which has nearly the same 

 carbon isotope ratio as the marine belemnite standard. The isotopic compo- 

 sition of carbon appears to be more diagnostic in the samples studied. 

 There is some overlap in points representing marine and fresh-water lime- 

 stones, but the separation is good enough to justify the conclusion that 

 measurement of the isotopic composition of carbonate carbon offers a prom- 

 ising criterion for environmental study of limestones. - J.L.M. 



2154 



Kellogg, J. L. 1915. 



Ciliary mechanisms of lamellibranchs with descriptions of anatomy. J. 

 Morphol. 26(4): 625-701. 



In Venus mercenaria material on outer and inner lamellae of both demibranchs 

 is moved to the free edges and forward to the palps. A tract between the 

 gills, at their bases, moves particles forward to meet those brought on the 

 margin of the outer demibranch, and all is moved downward to the lateral 

 groove. On the outer faces of the palps, cilia streams move around the 

 dorsal margins to the inner or apposed faces. Most material usually moves 

 on to the palp folds and is then disposed of. Palps are narrow and respond 

 to touch with great contortion, so that they are not easily studied. High 

 on the side of the visceral mass the trend of general ciliation is forward. 

 Movement of particles is rather directly toward its posterior wall from which 

 it is thrown off to the mantle. Some part of the collection may be sent to 

 the dorsal margin of the palp, and if not of too great volume, may ultimately 

 reach the mouth. A distinct line, or narrow path, extends over the mantle 

 from a point near lower edge of anterior adductor to base of incurrent si- 

 phon. A general ciliation, without definite lines or tracts, covers the rest 

 of mantle wall, and everything on these cilia is moved to the line. An ap- 

 pearance of definite lines or tracts may be seen when a mucus mass is drawn 

 out in a long thread. Waste accumulates in a bay just below the base of 



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