194 



THE AMERICAN 



common American species of the worm I have 

 named the Variahle Gordius (G. varhcs) from 

 its presenting some variety of character. 



The worm is cylindrical, of pretty uniform 

 diameter, but slightly narrowed at the ends. It 

 is smooth and lustrous, and varies from a light 

 yellowish-brown to a chocolate-brown, some- 

 times nearly black. It is usually much coarser 

 than a horse-hair, to which it is so commonly 

 likened. The head end is marked by a ring" of 

 darker color (see Fig. 119, a) than the rest of 

 the body. The ring appears darker in contrast 

 with the lighter condition of the latter, and 

 may be obscured entirely in the nearly black 

 varieties (Fig. 119, b). The summit of the 

 head appears as a convex whitish prominence 

 Included within the ring, and is composed of a 

 thinner membrane than the rest of the integu- 

 ment. 



[Fig. 120.] 



The tail end of the male makes one or two 

 spiral turns, and terminates in being forked. 

 The tail end of the female is straight, and ends 

 in three lobes (Fig. 120, g h). The male varies 

 in length from 4 to 6i inches, with the thickness 

 from 1-5 to } of a line. The female ranges in 

 length from 5 inches to a foot, with the thickness 

 from 4 to J of a line. 



The males of this, which I have regarded 

 heretofore as of one species, present two varie- 

 ties, each of which I now suspect to indicate a 

 diflereut species. In the one variety, usually 

 more robust than the other, the forks of the tail 

 are not longer than the thickness of the body — 

 as seen in Figure 120, k, which represents a 

 dorsal view. Between the base of the forks, 

 on the ventral surface (Fig. 120, i), there 

 is included a crescentic fold in which may be 

 seen the genital pore. In the other — usually of 

 more slender form— the forks of the tail are two 

 or three times the length of the thickness of the 

 body (Fig. 120, l), and the forks do not include 

 at their base a crescentic fold as in the former. 

 The genital pore is a little in advance of the 

 division of the tail. The species, probably indi- 

 cated in this last form, might be distinguished 



by the name of the Long-lobcd Gordius ((r. 

 longilobatus) . 



A more delicate species than the former I have 

 named the Linear Gordius (G. Uneatus). It 

 was indicated by half a dozen specimens ob- 

 tained by Prot. S. F. Baird, from a spring in 

 Essex county. New York. It is of a light clay- 

 color, and has no dark ring encircling the head, 

 which is represented in Figure 119, c. The tail 

 end of tlie male (Fig. 120, m) is forked very much 

 as in the Long-lobed Gordius, but the forks are 

 furnished on their inner margin, ventrally, with 

 a fringe of minute processes, such as are repre- 

 sented, highly magnified, in Figure 120, n. The 

 tail end of the female is blunt and unprovided 

 with lobes, the genital pore occupying the 

 centre of the extremity, as seen in Figure 119,/", 

 the similar end of a larger species, to be next 

 described. The male measures from 5 to 7 inches 

 in length, by l-6th of a line in thickness. A 

 single female accompanying the males was 5 

 inches long and l-5th of a line thick. 



Numerous specimens of a much larger species 

 of Gordius than any of the preceding, were sent 

 to me some years ago by Dr.Wm. A. Hammond, 

 who obtained them 525 miles west of Fort Riley, 

 Kansas. They were discovered in large num- 

 bers in a pond, in company with the curious 

 batrachian Siredon, or so-called Fish-with-legs. 

 They swam actively just beneath the surface of 

 the water, and occasionally protruded the head 

 above into the air. They are of a light yellow- 

 ish-brown, with the head end encircled by a 

 narrow band of darker hue, as represented in 

 Figure 119, e. The males are darker than the 

 females. The tail end of the former resembles 

 that of the male ofthe Variable Gordius (Fig. 120, 

 i k). The tail end of the female (Fig. 119,/) is 

 blunt, and exhibits the genital pore in the centre 

 surrounded by a brown ring. The body of this 

 Gordius is more anuulated than in any of the 

 other.species. The males measure from 8 inches 

 to 2 feet 2 inches in length, and 1-4 to 2-5ths of 

 a line thick. The females measure from 10 

 inches to 2 feet 6 inches iu length, by Jd to 3-5ths 

 of a line thick. 



The species I think to be the same as one pre- 

 viously described by me, under the name of the 

 Robust Gordius (G. robustus), from a female 

 specimen, about 6 inches in length, which was 

 found parasitic in a Grasshopper {Orchelimum 

 gracile), in New Jersey. Certain it is, the lat- 

 ter agrees in all details with the female speci- 

 mens from Kansas, except in size. The great 

 Helminthologist, Dr. Diesing, of Vienna, from 

 my description, named the species Gordius sub- 

 spiralis. 



