1379 



Nelson, Julius. 1914. 



Report of the biologist. In Ann. Rept. N.J. Agric. Coll. Expt. Sta.: 489-535. 



Plankton samples for oyster larvae also contained clam larvae, presumably hard 

 clam. These were almost always present, but it was noted that they look so 

 much like oyster larvae at some stages that identification was difficult. 

 Table IV records samples taken from 13 June 1913 to 21 August at Barnegat 

 Station and from 2 6 June to 10 Sept at Edge Cove Station. Clam larvae were 

 present until July 7 at Barnegat, and present only intermittently thereafter. 

 At Edge Cove clam larvae apparently were less abundant, and appeared mainly 

 for short periods in mid-July to the end of July. - J.L.M. 



1380 



Nelson, Julius. 1916. 



Report of the Department of Biology. In Ann. Rept., N.J. Agric. Coll., 

 Expt. Sta.: 239-260. 



In July 1915 the newly organized State Board of Shell Fisheries began its 

 work, succeeding the Bureau of Shell Fisheries and several oyster commissions. 

 This report makes passing reference to a study of green clams (species not 

 identified) in 1892. It is suggested that this might be associated with 

 oxygen deficiency. An annelid larva which is rather abundant in the plankton 

 in June and July -(and apparently suspected as a predator of bivalve larvae) 

 could not feed on oyster or quahog larvae because they are larger than the 

 worm. - J.L.M. 



1381 



Nelson, Thurlow C. 1918. 



On the origin, nature, and function of the crystalline style of lamellibranchs. 

 J. Morph. 31(1) : 53-111. 



Studies were made on American oyster, ribbed mussel, and Venus mercenaria. The 

 paper also reviews the literature on the crystalline style of lamellibranchs 

 and corrects some misapprehensions. Previous workers had surmised from its 

 structure that the style rotates, but the author believed that he was the 

 first to observe the rotation directly. Food material in the stomach of the 

 veliger larva of Venus is in constant rotation. This is caused largely by 

 the action of 2 groups of large cilia. It is always clockwise viewed from the 

 anterior end of the larva. In position and direction of stroke these 

 correspond to those of the adult. The period of rotation of the crystalline 

 style in the adult is quite rapid. It also is clockwise from the anterior end. 

 Food material in the stomach, entangled in mucus, becomes wound around the head 

 of the style, and is whirled around in the lumen just posterior to the gastric 

 shield. Strings of mucus from any part of the body, if led to the stomach 

 cavity, are at once drawn in and wound up in the food mass. The cilia of the 

 style sac push it anteriorly against the gastric shield with force enough to 

 cause the style to bow out when the stomach walls are drawn apart. The style 

 arises as a thin core of bubbly mucus, upon which are deposited co-axial 

 layers of a gelatinous protein, containing enzymes. Movement of the style 

 is important in separating food from foreign particles and in serving as a 

 substitute for peristalsis. The gastric shield protects the gastric mucosa 

 against the abrasive action of the head of the revolving style. The style 

 contains strong amylolytic ferments held in a stiff gelatinous matrix of a 

 globulin-like substance. - J.L.M. 



388 



