66 THE NAUTILUS. 



of writers to use just such evidence to advocate the theory of a 

 fluviatile origin for the widely distributed beds of loess in the 

 Missouri Valley region. 



By passing a quantity of the material from the shell zone over 

 a set of sieves of different mesh. I was enabled to recover a 

 number of very minute species, some of them, notably Cary- 

 chium exile Lea, being quite abundant. 



List of species from the government quarry near Mokane, Mo. : 

 Polygyra albolabris, (a) Pyramidula solitaria, (c) 



Polygyra appressa, (a) Pyramidula alternata, (a) 



Polygyra appressa, small Pyramidula alternata, small 



var., (c) var., (c) 



Polygyra elevata, (a) Gastrodonta ligera, (r) 



Polygyra multilinear, (r) Helicodiscus parallehis, (c) 

 Polygyra thyroides, (c) Vallonia pulchella, (a) 



Polygyra zaleta ?, (c) Vallonia sp. indet., (r) 



Polygyra fratema, (c) Bifid aria contracta, (c) 



Polygyra monodon, (c) Bifidaria armtfera, (c) 



Polygyra hirsuta, (c) Bifidaria procera?, (r) 



Zonitoides arborea, (r) Carychium exile, (a) 



Zonitoides minuscula, (c) Helidna occidta, (c) 



(a) == abundant, (c) == common, (r) == rare. 



THE FEEDING H \BITS OF BUSYCON. 



BY SHIELDS WARREN. 



Last September I made a series of observations on the feed- 

 ing habits of Busycon at Hyannisport, Massachusetts. This 

 place was well suited for the work, since both B. canalicidata 

 and B. carica occur plentifully, and oysters and quahaugs are 

 fairly numerous. All these observations were made under 

 natural conditions. 



There are two distinct stages in the feeding habits, the first 

 when the animal is small and the shell weak, the second when 

 the animal is grown and the shell strong. In the first stage 

 they are incapable of attacking a large lamellibranch, and eat 

 carrion and small univalves, such as Nassa, which o.ccur abund- 



