1851.] 



263 



Gordius was obtained by Professor Baird from a spring in Essex county, New- 

 York. It is very much more delicate than the former, and from 5 to 7 inches 

 long. The female caudal extremity is blunt The male caudal extremity is bi- 

 furcate and fringed with peculiar epidermoid appendages. 



For this second species the name Gordius lineatus was proposed. 



Dr. L. also had found several remarkable species of Mermis, Dujardin. 



Eleven specimens of one species were procured by Dr. Budd from a ditch in 

 New Jersey. These are yellowish white in color, and from 6 to 18 inches in 

 length. To the species the name Mermis elongata was given. 



A second species was found in a ditch near Philadelphia. It is pure white in 

 color, 8 inches long, and has a peculiar tubercular thickening of the integument 

 upon the caudal extremity. For this species the name Mermis crassicaudatawas 

 proposed. 



Dr. L. further remarked that he had lately had an opportunity of repeating his 

 former investigations* upon the embryology of Gordius varius. 



The embryology of Gordius aquaticus, L., had been studied and published by 

 Grubyf before he had published his notes, but he did not know it at the time, 

 which he considered important, as the observations conducted in two parts of the 

 world, though differing in several specific points, were generally confirmatory of 

 one another. 



The perfect embryo of Gordius varius differs so much from the parent that it 

 is impossible to recognise the latter in the former. This has two circles of pro- 

 tractile tentaculas, each of six, and a protractile proboscis, not uncinate, however, 

 as in the embryo of Gordius aquaticusj, no trace of which exist in the parent. 

 The body of the embryo consists of two portions, and is distinctly annulated, 

 while the parent is simply hair-like in form, and has no trace of an annulated in- 

 tegument. Gruby remarks he never saw the Gordius, excepting the embryo, 

 shorter than 31 inches, so that between the annulose, tentaculated embryo, in the 

 Gordius varius the l-466th of an inch in length, and the parent of at least 3| 

 inches, nothing whatever is known of the history of the animal. Gordii have been 

 stated upon numerous and the most reliable authorities to have been seen in the 

 body of insects, so that from the embryo to the parent, there may probably be a 

 series of forms in alternating generation, entozoic and ectozoic, as numerous and 

 unlike as has been observed in the development of certain species of Distoma. 



The Gordius varius is prolific in a very remarkable degree. A female 9 inches 

 in length placed in a tumbler of water, September 25th, up to the present time 

 has extruded a string of ova 49 inches in length and still actively continues the 

 process. 



September 16th. 

 Vice President Bridges in the Chair. 



Dr. Le Conte, of New York, read a continuation of his paper, entitled 

 " An attempt to classify the Longicorn Coleoptera of the part of 

 America north of Mexico ;" which being intended for publication in 



Proc. Acad. Nat. Sci., Vol. 5, p. 98. 

 t Archiv fur Naturcesch. 1819, p. 358, 

 + Ibid, pi. 7, fig. 10. 

 Ib. p. 374. 



