I04 RRSR ARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 



Gordiiis triciispidatns ^ Seibold. Zeits. F. Wiss. Zool., vii, 143 

 (1855). Body long, linear, cylindrical, attenuated towards the ex- 

 tremities ; narrowest anteriorly ; passing through a variety of shades 

 from a dusky yellowish white or cream color to a dusky ochreous 

 yellow, yellowish brown, reddish brown, light chocolate to dark 

 chocolate brown, or to ebony black ; lustrous, often iridescent in sun- 

 light. Head surrounded by a dark-brown or black ring, obliquel}' 

 truncated and terminated by a convex, translucent, whiti.sh vesicu- 

 lar membrane, at the lower part of which is a minute round mouth. 

 Integument areolated ; areolae irregularly pentahedral. 



Female. — Lighter in color than the male, and usually much longer 

 and thicker. Caudal extremity trifurcate ; caudal lobes elongated, 

 elliptical ; one narrower than the other two. Generative aperture 

 round, enclosed by the caudal lobes. 



Male. — Usually dark brown, often inclining to black. Caudal 

 extremity curved. Tail bifurcate ; caudal lobes curved conoidal, 

 obtu.se, divergent. Generative aperture ventral, just above the 

 caudal lobes. Twenty females and twelve males were found in 

 Rancocas creek, a branch of the Delaware, New Jersey, in the month 

 of August. Length of the former 5 to 12 inches ; breadth i-4th to 

 2-5ths of a line. Length of the latter from 4 to 6^2 inches ; breadth 

 I -5th to I -4th of a line. Three females from 7 to 1 2 inches in length , 

 and from i-4th to 2-5ths of a line in breadth ; and one male 6^ 

 inches in length and i-4th of a line in breadth, were obtained from 

 the Schuylkill river. Mr. Pearsall has given me eight specimens 

 from Philadelphia county. Professor Agassiz has given me a female 

 12 inches in length from Niagara ; a male 6 inches in length and a 

 female 8 inches in length from the vicinity of Cambridge ; two 

 females 6 inches in length from Edgartown, and a male 3 inches in 

 length, and two females 4 inches and 9 inches in length from Tren- 

 ton. Dr. King, of Greensburg, Pa., has given me a male 5 inches 

 in length, from his vicinity. Mr. Hazard, of Point Judith, R. L, 

 has given me a female 10 inches in length by 2-5ths of a line in 

 breadth, from his vicinity. Professor Kirtland has given me a male 

 5 inches in length, said to have been passed per anum by a girl, 

 near Cleveland, Ohio. Professor Baird has given me three males 

 from the Susquehanna river, near Carlisle, Pa., and a male and 

 female from Lake Champlain, N. Y. 



The Gordius varius is the most common species of the genus in 

 the United States, and is familiar to most persons under the name 

 of hair-worm, and is erroneously supposed to originate from the 

 maceration of hor.se hairs in water. The species is remarkably pro- 



