abstracts: parasitology 19 



The iron-bearing formation of the Cuyuna district presents a variety 

 of lithologic types. Among the more common rocks composing it are 

 hematitic and Hmonitic chert and slate, cherty and slaty iron carbonate, 

 siliceous magnetitic slate, amphibole-magnetite rock, jaspilite, dark- 

 blue, red, brown, black, and yellow iron ore, black, red, and brown 

 manganiferous iron ore, green chloritic schist, and dark-red hematitic 

 schist. 



It is generally supposed that the original rock frorn which the present 

 hematitic and Hmonitic chert and iron ore have in large part been 

 formed is a banded cherty iron-carbonate rock. 



The ore bodies are as a rule roughly tabular in shape, with the longer 

 axes parallel to the bedding of the inclosing rocks. As the beds of 

 rock generally dip steeply, the ore bodies are shown at the surface as 

 bands that extend for considerable distances along the strike of the 

 beds. They range in width to several hundred feet and are usually 

 very long, some of the known ore bodies being more than a mile in 

 length. The Cuyuna ore shows all stages of hydration from pure 

 reddish-blue hematite to ocherous yellow limonite, and both argillace- 

 ous and siliceous phases are common. R. W. Stone. 



PARASITOLOGY. — A further note on the life history of Gongylonema 

 scutatum. B. H. Ransom and M. C. Hall. Journ. Parasit. 

 3: 177-181. June, 1917. 

 Seurat in recent publications has questioned certain conclusions 

 reached by the writers in former papers relative to the life history of 

 the nematode Gongylonema scutatum. In the present paper these 

 conclusions are upheld, namely that dung beetles and croton bugs 

 fed upon the eggs of G. scutatum become infested with an encysted 

 larval stage of the parasite and that it is quite evident that sheep, 

 cattle, and other suitable mammalian hosts become in turn infested 

 as a result of swallowing infested insects (under natural conditions 

 various species of dung beetles). Certain larval nematodes found by 

 Seurat (1916) in several species of Blaps in Algeria are not G. scutatum 

 and it is not improbable that those which he found in various Algerian 

 beetles and identified as the larvae of G. mucronatum Seurat in reality 

 belong to the species G. scutatum. B. H. R. 



