284 [October, 



These are very common in the still waters, and mud, in all parts of the State. 

 They are usually about the size of a large horse hair, and are from one to six or 

 eight inches in length. In color they vary from pure white to nearlj' black, and 

 hence we probably have several species. The vulgar notion that they originate 

 from hairs which fall from horses and cattle, and become animated in the water, 

 would seem to be too absurd for contradiction ; and yet, absurd as it is, people 

 are to be found who believe it."* 



The same popular opinion is prevailing in Europe. Gordii have been noticed 

 in the body of insects, also, by an American entomologist, Dr. Th. Wm. Harris, 

 who says : " I have taken three or four of these animals out of the body of a 

 single locust."! 1'hey have been found, by others, within the cricket, {Acheta 

 ahbreviuta). 



We saw a specimen, six or seven inches in length, caught in the clear waters 

 in the vicinity of Richmond, (Va.) Several others were detected by Dr. Leidy 

 in the neighborhood of Philadelphia. 



Finally, we may mention several specimens of Gordii from Oregon, brought 

 home by the U. S. Exploring Expedition. 



Gordii, therefore, are spread all over the Western hemisphere. 



The Committee on the following paper, by Dr. Leidy, reported in 

 favor of its publication in the Proceedings. 



Corrections and Additions to former Papers on Helminthology pullished in the 

 Proceedings of the Academy. By Joseph Leidy, M. D. 



BODO, Ehrenberg. 

 1. BoDO Helicis, Diesi7ig: Syst. Helm, i, 45. 



Cryptobia Helicis, Leidy : Proc. A. N. S. iii, 101 ; An. and Mag. of Nat. 

 Hist, xix, 209. 



Cryptoicus Helicis, Leidy: Joum. A. N. S., new series i, 67. 



VERTEX, HeiTb-prich et Ehrenberg. 



1. Vertex maeginatus, Dicsing: Syst. Helm, i, 229. 



Prostoma marginatum, Leidy: Proc. A. N. S. iii, 251. Rarely more than 

 3-5ths line long. Abundant in ditches below the city of Philadelphia. 



AORURUS, Leidy: Pr. A. N. S. iv, 230. 

 Characteribiis reforonatis. Body cylindroid, broadly and strongly annulated 

 Tail long, spiculate, and inflexible. Mouth simple, round, unarmed. Female 

 generative aperture posterior to the middle. Male with a single spiculate penis. 



1. Sub-genus. STREPTOSTOMA, Leidy: Pr. A. N. S. iv, 230. 

 Characteribus reformatis. Annuli very broad, distinct, and few in number. 

 Mouth large, circular ; buccal organ {(esophagus) and gizzard pyriform. Tail 

 very long, and ensiform. 



* Natural History of Vermont, 1S42, Svo., p. 170. 



t Report on the Insects injurious to vegetation, -1842, p. 155. 



