232 ; 
Tue Hasits of AmBiyopsis. By C. H. EIGENMANN. 
Tue Buryp SALAMANDERS OF NorTH AMERICA, WITH SPECIMENS. 
By C. H. E1cENMANN. 
Nores ON THE EMBRYOL’GY OF PARAGORDIUS (GORDIUS) VARIUS (LEIDY). 
By AxsBert B. ULREY. 
[Abstract. ] 
During the latter part of last summer I had the good fortune to find 
a lot of eggs of Paragordius (Gordius) varius (Leidy). This small thread- 
worm is familiar to nearly every one as the common horsehair worm 
found in streams, ponds and frequently in watering troughs. 
The life history of the worm is known, in a general way, to all zodlo- 
gists. It is well understood, of course, that the very common supersti- 
tion regarding the origin of the worm from the horse’s hair has no more 
foundation in fact than a superficial resemblance. 
There are three well-marked phases in the life history of Gordius. 
First, a free living larval stage. Second, a parasitic phase in which the 
host is (a) some aquatic insect, and later on (b) more commonly the fish 
becomes infested by feeding on the insect containing the larvae. Third, 
the adult or sexually mature stage. 
While the general course of development has been known for a num-. 
ber of years, there still remains much uncertainty concerning the details 
of its development, and there is absolutely nothing known as to many 
points in its life history. As a result of these gaps in our knowledge of 
these animals their relationships are not well understood. Some investi- 
gators believe that their affinities are with the segmented worms, while 
others maintain that they are to be grouped with the Nematodes. 
It was with the belief that a more complete knowledge of the details 
of development of these forms might throw some light on their systematic 
position that I began this study. 
The work is beset with numerous difficulties, among which may be 
mentioned the extremely minute size of the egg and the well-known difli- 
culty of sectioning eggs of this character. I have given my attention thus 
