666 REPORT UNITED STATES GEOLOGICAL SURVEY. 



carnivorous beetles, such as dififereut species of CaraMdce. They live 

 in or around the fat body, and sometimes twine around the intestines 

 of their host, and finally pass out of the anus. As the carnivorous in- 

 sects are liable to devour the larvse of other insects living in damp 

 places, it is not difficult to see how they should become tenanted by 

 young hair-worms encysted in their victims, but why they should be so 

 common in grasshoppers is not so easy to deteriuine. Grasshoppers 

 probably take the minute larva) with their food, and fields recently in- 

 undated are of course more liable to abound with them. They also 

 live in fish and frogs, and "Diesiug sj^eaks, on the authority of Kirkland, 

 of a young girl in Ohio who had expelled per ano a, Gordius varius. It 

 is the popular belief in Europe that they live in man, and that they 

 may be introduced in drinking water from brooks and pools, or in eating 

 fish not properly cooked. In this country they seem to occur not un- 

 commonly in the bodies of grasshoppers, and are useful in keeping them 

 in check. 



Description of the species occurring in the United States. — The following 

 descriptions are taken from Villot's Monograph, and embrace all up to 

 this time known to inhabit this country, a few notes of my own being 

 added : 



Gordius aquations Linn (Plate LXIII, Fig. 7, a, /, i, and k). — Anterior end rounded, 

 distinctly swollen. Posterior extremity of the male bilobate, recurved beneath ; lobes 

 distinctly hollowed within and abundantly provided with papillaj; a crescent-shaped 

 fold of the epidermis beneath the ano-genital opening. Posterior extremity of the 

 female truncated perpendicularly to the axis; ano-genital opening central, surrounded 

 ■with a reddish-brown circle. General coloration varying from milk-white to brown ; 

 a horny, transparent cap and a deep-brown ring at the anterior extremity; body be- 

 sprinkled with numerous circular spots of a yellowish- white. Epidermis smooth, divided 

 into lozenges by salient lines crossing obliquely. Dimensions very variable ; length, 

 28-89 centimeters ; breadth, J to 1 millimeter. 



Habitat : Europe and North America (Leidy and Girard). A male of this species 

 from Gryllus ncglcctns June 5, Pittsburgh, Pa. (B. C. Jillson), and a female from Tops- 

 field, Mass., are in the museum of the Peabody Academy of Science at Salem. I have 

 received a female of this sjiecies from Prof. C. V. Riley, said to have been a parasite of 

 Caloptenus spretus in Missouri. It is probably common all over the country east of 

 the Rocky Mountains. 



Gordius lUieatus Leidy. — Posterior extremity of the female obtuse ; that of the male 

 bilobed and furnished with jiapilhe. Length, .5 to 7 inches. (Leidy). Essex County, 

 New York. Diesing cites it among the synonymes of Gordius aquaticus. 



Gordius 7-ohustus Leidy. — Posterior extremity a little compressed and obtuse. Body 

 stiff, marked with transverse folds 6 inches long. Pemberton, N. J. From a grass- 

 hopper (Leidy). Diesing refers it to Gordius aquaticus. A female which agrees with 

 this S2>ecies, from the body of Stenopehnata fasciata Thomas (identified by Mr. Thomas), 

 Wahsatch, Utah (L. E. Ricksecker), is contained in the museum of the Peabody Acad- 

 emy of Science. The posterior extremity is compressed, except at the extreme end, 

 which is cylindrical. The ano-genital orifice is sunken. The body appears as if irreg- 

 ularly segmented, being marked by transverse, impressed lines. Head conical, more 

 acute than in aquaticus, and paler. This specimen was 10 inches long, of the same 

 size and proportions as G. aquaticus, and would at first bo mistaken for it. 



Professor Leidy states in the American Entomologist (ii, 194) that a female of this 

 species, about 6 inches long, was found parasitic in a grasshopper, Orcheliinum gracile, 

 in New Jersey. 



Gordius subspiralis Diesing. — Body of the male brown ; that of the female attenu- 

 ated in front, of a clear brown, brilliant, irised. Head surrounded with a ring of an 

 obscure brown. Caudal extremity of the male terminated by two diverging lobes, 

 spiral, recurved beneath, smooth, joined to their base by a membranous fold ; that of 

 the female obtuse, a little compressed. Dimensions of the male : Length, 8 inche8-2 

 feet 2 inches; thickness, J-* of a lino; female, 10 iuche8-2 feet 6 lines ; thickness, J-f- of 

 a line. 



Ilahitat : Common in a pond 525 miles west of Fort Riley, Kansas, which would 

 place the habitat in Central Colorado, where it lives in company with Siredon (Hain- 

 mon). Diesing, who made the species known in 18G0, referred to it a Gordius, -which 

 Leidy had mentioned without a specific name in 1857. 



Gordius fasciatus Baird.* — Body furrowed with cross-lines, attenuated in front and 



'Proceedings Zoological Society London, 1853, 21, pi. xxx, f, 6. 



