1348 



Morrison, G., E. Jackim, and K. Bonatti. 1977. 



Use of an inert radioactive particle for measuring particle accumulation by 

 filter-feeding bivalve molluscs. Mar. Biol. 40(1): 51-55. 



Meraenaria (Venus) meraenaria is not mentioned. - J.L.M. 



1349 



Morse, Edward S. 1881. 



The gradual dispersion of certain mollusks in New England. Bull. Essex 

 Inst. 12: 171-176. 



The author traces the rapid diffusion of Littorina litorea (sic) from 

 Kennebunk, Maine in 1870 to New Haven, Conn, by 1880. No mention is made 

 of Meraenaria (Venus) meraenaria . - J.L.M. 



1350 



Morse, Edward S. 1919. 



Observations on living lamellibranchs of New England. Proc. Boston Soc. Nat. 

 Hist. 35(5) : 139-196. 



The mantle of Venus meraenaria is fringed, but with more uniformity than 

 Cytherea aonvexa. It is light salmon color. At its junction with the 

 branchial siphon it shows rather large digitations; viewed from below, the 

 folds of the mantle appear very close together and interlock. Foot short 

 and broad, occupying nearly entire length of ventral margin of shell. 

 Siphons are united, very short, and of nearly equal diameter, the branchial 

 siphon larger. The margins of the openings are fringed with very small 

 papillae crowded together; these vary slightly in length, a few are 

 bifurcated. Anal papillae alternate long and short, branchial papillae not 

 so alternating. Siphonal walls are thin and mottled, with minute black 

 blotches. The siphonal valve in young is quite conspicuous, but the author 

 had never observed it in adults. When the shell rests on its side the 

 siphons turn upward at right angles to the long diameter. In the very young 

 shell the hinge margin posterior to the beak is straight. The shell is 

 marked with high concentric ribs. Siphons of young are long and narrow, with 

 a conspicuous valve which is light yellow with black mottlings. Adult and 

 young are illustrated, with details of siphonal openings. - J.L.M. 



1351 



Morton, Brian. 1973. 



A new theory of feeding and digestion in the filter feeding lamellibranchia. 

 Malacologia 14(1-2): 63-79. 



This comprehensive review paper concludes that although it had previously 

 been believed that filter-feeding lamellibranchs feed and digest their food 

 continuously and simultaneously, this is not so. These processes are 

 rhythmic and related to environmental rhythms. In time and space, feeding 

 is dynamic. Food is first collected, filtered, selected, and passed to the 

 stomach. Then food collection ceases and accumulated food is digested. The 

 evidence is traced from rhythmic adduction of shell valves, to changes in 

 constituents of stomach fluids over a tidal cycle, to intermittent secretion 

 of style material and dissolution of the crystalline style, to the fact that 

 the gastric shield is enzymatically active and not simply protective, and to 

 rhythmic sorting or storage in stomach, appendix, and digestive diverticula. 

 A number of misinterpretations and misunderstandings are cleared up. Many 

 lamellibranch species are discussed. Evidence is included that daily rhythms 

 have been detected in Venus meraenaria, as well as monthly and 27-day cycles. 

 The extensive list of literature contains 110 citations. - J.L.M. 



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