RESRARCHES IN HELMINTHOLOGV AND PARASITOLOGY. 33 



Length 2 lines ; greatest breadth i-ioth inch ; greatest thickness 

 3-5th line. Proboscis }( line. 



Habitation. — Two individuals were found in the iliac portion of 

 the small intestine of Felis leopardis. 



6. Echinorhynchiis Tortuosus. — Body brownish white, opaque, very 

 much contorted and transversely corrugated, subcompressed, dilated 

 just below the middle, attenuated towards the extremities, most so 

 anteriorly, posteriorly recurved and obtuse. Neck short. Head 

 subglobular, armed with four rows of simple recurved hooklets. 



Length 2 inches 8 lines ; greatest breadth i-yth inch ; greatest 

 thickness i line ; diameter i line from the neck i-5th of a line ; 

 from the posterior extremity 4-5ths of a line. Proboscis and neck 

 i-5th line long. 



Habitation. — Found with the anterior 3 lines of its length buried 

 in an oval tumor 4 lines in diameter in the mesenter}- of a Didel- 

 pJiis Virginia na . 



7. Echinorhynchus Pici collaris. — Body white, opaque, sub-cylin- 

 drical, sub-compressed, and curved posteriorly ; transversely corru- 

 gated and slightly so longitudinally, moderately dilated anteriorly. 

 Neck very short. Proboscis short, cylindrical, contracted in the 

 middle, with the free extremity rounded and furnished with four 

 rows of simple recurved hooklets. 



Length i inch 8 lines ; breadth anteriorly i-ioth inch ; thickness 

 i-i2th inch ; posteriorly 4-5ths line broad by 3-5ths line thick. 

 Proboscis 4-5th line long ; thickness }^ line. 



Habitation. — Intestine of Picns collaris. 



Remarks .—Y)'\'&.^rs from the E. Pici, Goeze,* which has a long 

 linear proboscis, with 8 or 10 ranges of hooklets, and is narrower in 

 front than behind, just the reverse of the species just described. 



[October, 1850. No. 57. See Bibliography.] 



NOTES ON THE DEVELOPMENT OF THE GORDIUS AQUATICUS. 



Just four years ago I exhibited to the Academy a mass of living 

 hair-worms or Gordiiis aquaticns, consisting of fourteen individuals 

 strangely knotted together, and recalling the appropriateness of the 

 Linnean name. 



It is a vulgar opinion that the Gordiiis is a horse hair which has 

 become vivified from maceration for several weeks in a spring or 

 pool of fresh water, an error which has probably arisen from their 



* Naturgeschichte S. 151, Taf., 11. 



