PROCEEDINGS 



OF THE 



ACADEMY OF NATURAL SCIENCES 



OP 



PHILADELPHIA. 



1881. 



January 4, 1881. 

 Dr. Jos. Leidy in the chair. 

 Twenty persons present. 



Bhizopods as Food for Young Fishes. — Prof. Leidy remarked 

 that last September he had received a letter from Mr. S. A. Forbes 

 of the Illinois State Laboratory of Natural History, Normal 

 Illinois, stating that the 3'onng of some of the suckers {Catasto- 

 midse), Hi/jjentelium, Myxostoma, etc., " have the intestines packed 

 with tests of Difflugia and Arcella.^'' Later, Mr. Forbes sent two 

 slides, with some of the intestinal contents, for examination. 



The slide with food from the intestine of the large-scaled Mullet 

 Myxostoma macrolepidotum, from Macinaw Creek, contained the 

 following species: 



DiFPLiTGiA GLOBULOSA. Shell of rather coarse sand, with laroer o-rains 

 around the mouth ; mostly in the shape of the segment of an oval" with 

 the oral pole truncated. Most numerous form. 



Measurements of a number were c^s follows : 



1. Shell 0.18 mm. long ; 0.162 broad ; oral end, 0.103 broad. 



0.18 



0.156 



0.174 



0.198 

 0.198 



0.156 



0.15 



0.156 



0.168 



0.31 



0.103 

 0.073 

 0.09 

 0.096 

 108 



Difflugia acuminata. Shell mostly slightly unsymmetrical • some 

 with a slight neck, straight or slightly everted at the mouth ; a few with 

 3 



