muscle cells are probably syncytial and are imbedded in a rather homogeneous 

 matrix. Mitochondria are localized and cytoplasmic bridges join the muscle 

 fibers. The nature of the nerve endings and relationship of cardioregulator 

 fibers to heart muscle cells have not been determined. It is speculated that 

 innervation is highly localized and that a wave of excitability spreads out 

 over the heart via the syncytium of ventricular muscle cells. - J.L.M. 



1161 



Loveland, R. E. 196 3. 



Some aspects of cardip-regulation in Mercenaria mercenaria . Ph.D. Thesis, 

 Harvard Univ. 



Not available in Dissert. Abstr . Internatl. - H.W.S. 



1162 



Loveland, Robert E.,and David S. K. Chu. 1967. 



Relating oxygen consumption to pumping rates in Mercenaria mercenaria. A. 

 Zool. 7(4): 738 (abstract 113). 



Oxygen consumption was measured at salinity 22 c / 00 and temp 25°C. Assuming 

 Q02 and pumping rate to be related the following equation predicts the 

 relationship: 



AP 



(p/cc) (t) 



,X n , where Y= 



pumping rate in L/hr, p=oxygen consumption in mis O2 , p/cc=oxygen tension, 

 t= time in hrs, and X= total wet weight in g. For constant salinity and 

 temp the equation converts to: 



Y=k c .QO2-X n+1 =(0.01414)X n+0 - 474 . - J.L.M. 



1163 



Loveland, R. E.,and S. 



Chu. 1969. 



Oxygen consumption and water movement in Mercenaria mercenaria. 

 Biochem. Physiol. 29: 173-184. 



Comp. 



Oxygen consumption in ml 02/g wet weight/hr declines with increasing wet 

 weight. Pumping rate increases with wet weight. Efficiency of withdrawal 

 of O2 was constant for clams of all weights: 2.91 1. of water pumped for 

 each 1.0 ml of O2 removed. Experiments were conducted at 25 C C and 22°/°° 

 salinity. It is not necessary to assume that a clam which can obtain its 

 required food intake from a relatively small volume of water, needs to pump 

 large quantities of water to supply the O2 needed to metabolize that food. 

 - J.L.M. 



1164 



Lowden, Ronald D. 



1965. 



The marine Mollusca of New Jersey and Delaware Bay (38°56' North Latitude to 

 40°30' North Latitude) an annotated checklist. Proc . Phila. Shell Club 

 1(8-9) : 5-61. 



The copy received from Univ. Calif. Library, Berkeley, is a xerox copy of a 

 typed manuscript, with no indication of the source. The date and citation 

 above are accepted as given. Phylum Mollusca, Class Pelecypoda, Order 

 Eulamellibranchia, Suborder Heterodonta, Superfamily Veneracea, Family 

 Veneridae, Subfamily Venerinae, Mercenaria (Mercenaria) mercenaria 

 mercenaria Linne, 1758, northern quahog, 3" to 5"; Gulf of St. Lawrence to 

 Florida and Gulf of Mexico; introduced to Humboldt Bay, Califj M. mercenaria 

 notata Say, 1822, 3" to 4"; locally associated with the typical form; 

 M. mercenaria alba Dall, 1902; M. mercenaria subradiata Palmer, 1927, locally 

 associated with the typical form. Included is a very detailed map of the 

 New Jersey coastline, giving many place names, with tidal data. - J.L.M. 



326 



