Dec., 1905.] 
Chelanops oblongus. 
417 
two pairs, an anterior and a posterior pair. When at rest the 
two anterior pairs extend forward and the two posterior pairs 
backward from a right angle with the body. When walking it 
uses its four pairs of legs quite as any four-footed animal uses 
its legs. When disturbed it contracts its abdomen, the latter 
thus becoming shorter and thicker. 
I focused the direct sunlight from a small engraver’s lens 
upon the desk, the specimen being under a watch glass. It 
appears that in a few instances the animal took note of the 
focus and went around it. It seems to have become conscious 
of the focus by reaching into it with its pedipalps. At other 
times it walked right through the focus without any concern 
whatever. Once I directed the focus upon the cephalothorax 
for some little time, when all at once it seemed to feel something, 
probably the heat of the focus, and it hurried away apparently 
discomforted. No eyes could be discovered, and the above 
experiments, I believe, simply indicate that the animal felt 
the heat of the focus. With a lens I could make out in many 
instances light circular disks near the anterior lateral margins of 
the cephalothorax. These were very suggestive of the so-called 
eye spots of the eyed elaters. 
Color. — The color of the adult is light brown, with the 
pedipalps, the dorsal ])art of the cephalothorax and the dorsal 
■[)lates of a darker shade. In newly moulted specimens the 
ajjpendages are of a light slate color, sometimes of a green or 
blue cast, or cream color, while the body is of a uniform yellow- 
ish brown or cream color, with the dorsal plates not well marked 
off. 
Economic Value. — To what extent these little animals serve 
any useful purpose in the destruction of insect pests, is not well 
known and difficult to determine. But, since they are carniv- 
orous, we may imagine that they destroy many small insects, 
larvae and mites that would otherwise be harmful; and if Bach- 
hausen’s observations are correct, many flies, and perhaps other 
insects larger than • themselves The book scorpion no doubt 
serves a useful purpose in keeping down the number of book-lice, 
and to what extent this is done might be a subject for investiga- 
tion. On the other hand a more complete study of the group 
may show us more clearly its economic value. 
The writer desires to express his sincere appreciation to Pro- 
fessor 0.sborn for his interest manifested in this paper and for 
the publication of the same as a University Bulletin. 
Biological Hall, Ohio State University, November 24, 190,5. 
LITERATURE. 
I. Balsan, Prof. Luigi. 1S91. Voyage de M. E. Simon au 
Venezuela, Arachnides, Chernetes. (fin) Ann. Soc. Ent. France. 
(Did not see first seventeen pages.) 
