624 



NEMA THELMINTHES 



Division. Family. 



r 



Genus. 

 r Triodontophorus 



Strongylid^ .. \ CEsophagostomum| 



Metastrongylidae Metastrongylus 

 f Nematodirus . . 

 ■ - J Haemonchus 

 Trichostrongylidsei 



I Trichostrongylus 



lAncylostomidae / Ancylostoma . 

 ^ y Necator 



Species. 



34. T. deminutus. 



35. QE. brumpti. 



36. CE. stephanostomum 



var. thomasi. 



37. M. apri. 



38. N. gibsoni. 



39. H. contortus. 



40. T. colubriformis. 



41. T. probolurus. ^ 



42. T. vitrinus. 



43. T. orientalis. 



44. A. duodenale. 



45. A. cey]a':icum. 

 4'^. N. americanus. 



It is not possible at the present moment to give a scientific and 

 , easily workable classification of the Nematoda, because the type 

 genera require revision. We group the various families under the 

 following divisions: — 



A. Nematoda in which the bursa copulatrix is merely a cuti- 



cular expansion not supported by true fleshy rays in the 

 males — Non-Bur sata. 



B. Nematoda with true bursa copulatrix — i.e., supported by 



fleshy rays in the males — Bursata. 



DIVISION NON-BURSATA. 



I.eiper gives the following table for differentiation of the non- 

 bursate families which are represented in the parasitic nematodes 

 of man:— 



A. Oesophagus a simple cellular tube — TrichosomidcB. 



B. QEsophagus a simple muscular bulb : — 



(a) Mouth surrounded by several protuberances. Male 



with one spicule; female with one uterus — Eiistror.- 

 gylididcB. 



(b) Mouth guarded by large fleshy jaws. Male with two 



spicules; female with two uteri : — 



(1) Jaws two in number: skin smooth— P/n\^^/o/ - 



teridce. 



Jaws two in niunber; skin spinous — Gnatho- 

 stomidcB. 



(2) Jaws three in number; skin striated — Ascaridcu. 



(c) Mouth a simple pore without buccal capsnle :• — 



(i) Female without vagina; embryos striated. Male 

 v/ith two equal spicules — Dracunculidce. 



