INSECTS INFESTED WITH HAIR-WOEMS. 



327 



external appearance. The commoner species of the former genus are 

 brown, while those of the latter are white or pale yellow. In reality, 

 some of those which are pale while within their host become dark after 

 issuance, and the color alone has no generic value. We need hardly 

 allude here to the popular belief that these worms are animated horse- 

 hairs. Despite the ready explo- 

 sion of the fallacy by naturalists, 

 the superstition is yet very prev- 

 alent, and we have several other- 

 wise intelligent correspondents 

 who persist in the popular faith. 

 The development of these Eutozoa 

 is, indeed, so obscure and difi&cult 

 to trace that their life-history is 

 yet enshrouded in some degree of 

 mystery, a fact which has no little 

 to do with the perpetuity of the 

 popular delusion. So far as pres- 

 ent knowledge permits, let us 

 glance at this curious life-history. 

 In the American Entomologist and 

 Botanist for May, 1870, Prof. 



posterior, tri-lobed 

 extremity of the female Vaiiable Gordins ; h. tlie 

 same, with the lobes more divergent, and exhibit- 

 lug the extrusion of the cord of eggs ; i, posterior 

 bi-lobed extremity of the male Variable Gordins, 

 seen on the ventral surface, and exhibiting the gen- 

 ital pore; k, dorsal view of the same; I, posterior 

 bi-lobed extremity of the male Long-lobed Gordins, 

 seen on the ventral surface, and exhibiting the gen- 

 ital pore ; in, the same in the male of the Linear 

 Gordius; », portion of the fringe of the latter, 

 highly magnified ; o, egg of the Variable Gordius, 

 containing a fully developed embryo highly magni- 

 fied. (After Leidy.) 



Joseph Leidy, of Philadelphia, 

 published what was- then known of these worms, and we quote here some 

 of his remarks. We are also indebted to Professor Leidy for a critical 

 examination and determination of the specimens we have studied.^^ An 

 interesting fact is worthy of mention here, as it may be more than mere 

 coincidence : it is that all the Orthoptera infested with these parasites 

 that have come under Mr. Eiley's notice (9 in number) are females. 



The Hair-worm is, however, a distinct animal, having no further relationship with 

 a horse-hair than in its general likeness, which is by no means an exact one. When 



83 The following specimens of hair-worms have been found infesting locusts, grasshoppers, katydids, 

 and crickets : 



Gordius seta, Miiller (aquaticus of other authors). — Two specimens (d" ?) from a $ Phylloptera oilon- 

 gifolia (De Geer). The (S has the dark annulns and pale truncated end, and also the anal bifid cha''- 

 acters of G. varius Leidy; but the $ has not the trifid anal chraacters of that species, and approaches 

 rohustus. Color light coflfee-brown. Length of cf ^5 inches ; diameter 0.8 mm. : length of 9 10^ inches; 

 diameter 0.9 mm. 0n6 cT from a 9 Orchelimum glaberrimum ; one 9 also Irom a 9 Caloptenu-s spretus. 

 All the above in Mr. Hiley's cabinet. Specimens of the same from water often show a transverse capi- 

 tal carina in the 9 . a°<l a dark longitudinal line the whole length of body. Mr. Packard has a <S taken 

 from Gryllus neqlectus, and has observed two specimens of what was apparently the same species in 

 Caloptenus bivittatus. 



Gordius rohustus, Leidy. — k. cf from 9 Anabrus purpurascens Uhler ; in Mr. Eiley's cabinet. Length 

 11| inches ; diameter 9 mm. Very similar to cT of preceding species, though the transverse striae are 

 more distinct. IMesing refers it to aqu.aticus, and it doubtless is specifically the same. J'ackard re- 

 cords a 9 from Stennpelmata fasdata, Thomas, taken at Wahsatch, Utah, and Leidy records a 9 from 

 Orchelimum gracile. 



Mermis albicans. — Two specimens from 9 Caloptenus spretus, one 17 the other 11 inches long; diam- 

 eter 0.6 mm. Anterior end quite tarering: neither capital nor anal characters that are noticeable. 

 One very long specimen, measuring 30 inches, from a Lycosa. One, evidently the same, but incomplete, 

 from a 9 Stenobothrus ; and one from a 9 Caloptenus differ entialis. All in Mr. Eiley's cabinet. 



Mermi6 acuminata, Siebold. — This species, according to European authors (Siebold, Meissner, and 

 Diesing), is but the parasitic non-sexual condition of M. (albicans, which they consider the external fe''- 

 tile or sexual condition. Both forms are, however, parasitic. Mr. Eiley has two specimens from a 9 

 Acridium americanum in the pupa etate, one of them measuring 16, and the other Hi inches ; also one 

 epeciraeu, Ah inches long, from a 9 CalojJtenus spretus ; also five specimens from the larva of Carpocapsa 

 pomonella, varying from 3 to 8 inches in length. A specimen of what was doubtless the same species 

 was seen by Professor Leidy protruding from CEdivoda caruUna while the latter was struggliiig in a 

 ditch. 



