No. 497] 



THE BUREAU OF FISHERIES 



327 



by another one centimeter below that, etc., until the whole 

 intestine was traversed. When the series had passed 

 three or four centimeters from the starting point, a new 

 series began. (2) A movement starting posteriorly and 

 passing forward, which consisted in a local shifting of 

 the wall towards the left, i. e., clock-wise with reference 

 to the axis of the valve viewed from behind. As shown 

 by small holes cut in the wall, the shifting of the wall 

 towards the left was accompanied by a shifting of the 

 inner folds towards the right. The effect must be a thor- 

 ough mixing of the food between the two surfaces. 

 (3) A large general shifting of the valve forwards, and 

 with a right rotation through about 180°. This was 

 caused by a great sheet of smooth muscle lying in the 

 mesentery between the genital gland and the spiral valve. 



Joseph F. Clevenger, M.A., acting professor of chem- 

 istry and biology, Wheaton College, Wheaton, 111.— The 

 Life History of Zostera marina and Ruppia maratima. 



Harold S. Colton, M.A., graduate student, University 

 of Pennsylvania.— How "Fulgur" and "Sycotypus" cat 

 Oysters, Mussels and Clams. The work, so far as per- 

 formed at Woods Hole, consisted of a series of experi- 

 ments and observations on the food of Fulgur and Sycoty- 

 pus (Btisycon carica and B. canaliculata), supplementing 

 some which were begun at the University of Pennsylvania 

 during the preceding winter. There had previously been 

 no complete account of the taking of food by those gastro- 

 pods. Stimpson (1860) and Ingersoll (1884) have men- 

 tioned their food; the former not completely and the 

 latter not correctly. The present studies dealt with the 

 kind and amount of the food and their manner of taking 

 it. (1) Although pieces of chopped oyster were found 

 to stimulate these mollusks, the latter were never ob- 

 served to eat them. B. canaliculata ate living Mya, 

 Ostrea and Mytilus, but refused Venus. B. carica ac- 

 cepted Mya, Ostrea, Mytilus, Modiolus, Ensis and Venus, 



