H^MONCHUS 



663 



Type Species. — Nematodirus filicollis Rudolphi, 1802. 



Remarks. — The subgenus Mecistocirrus Railliet, 191 2, with distinct cervical 

 papillae and cuticular ridges little apparent, contains the human parasite. 



Mecistocirrus fordi Daniels, 1908. 

 Synonym.— Nematodirus gibsoni Stephens, 1909. 



This worm was discovered by Belf in the faeces of a Chinaman in Hong 

 Kong, and described by Stephens. 



Morphology. — The male measures 21 millimetres by 0-4 millimetre, and 

 possesses an attenuated head with two cervical papillae, and a mouth with 

 two lateral papillae. The bursa shows two well-marked lobes, continued 

 dorsally on to the body as a V-shaped slit. There is one pair of ventral rays 

 and six pairs of dorsal rays — an anterior, two middle, and two posterior, 

 which last arise from a common stem. The spicules are very long (7 milli- 

 metres) and delicate. 



The female measures 25 millimetres long, and possesses a pointed tail, on 

 which the anus opens 0-2 millimetre from the tip, while the genital pore is 

 0'5 millimetre from the same extremity. The uterine egg measures 110 /j, 

 by 53 A^., 



Life-History. — Nothing is known as to the life-history. 

 Patliogenicity. — It is not stated whether it is 01 is not pathogenic. 



Haemonchus Cobb, 1898. 



- Synonyms —HcEMonchus Stiles, 1903 ; Strongyles O. F. MuUer, pro 

 ■parte, 



Strongylidae with unarmed mouth. Male bursa triiobed, with 

 median lobe asymmetrical, spicules short with an accessory piece ; 

 female with vulva situate posteriorly and protected by some tegu- 

 mentary appendages. 



Type Species. — Hcemonchus contortus Rudolphi, 1803. 



Haemonchus contortus Rudolphi, 1803. 



Synonyms. — Strongylus contortus Rudolphi, 1803; S. filicollis 

 Molin, 1861; 5. placet Place, 1893. 



This worm was found by de Magalhaes in a case of anaemia sup- 

 posed to be due to Ankylostoma duodenale, and from which the 

 specimens were obtained by treatment with thymol, after which 

 treatment the patient rapidly recovered. 



Morphology. — Body red or white, filiform, with attenuated extremities 

 Anterior extremity with two cervical papillse in the form of teeth directed, 

 backwards. Cuticle finely striated. Male: 10 to 20 millimetres in length, 

 with bursa provided with two lobes, of which the right carries an asymmetrical 

 median lobe. The two spicules measure 0*3 to 0-5 millimetre in length, and 

 are each furnished with an accessory portion. Female: 20 to 30 millimetres 

 in length, with caudal extremity pointed. Vulva situated in the posterior 

 fifth of the body. Eggs are ellipsoidal, 70 to 95 /j, long by 43 to 54 fj, broad. 



Life-History. — ^The eggs quickly develop when placed in pure or 

 muddy water, producing rhabdite embryos; the latter undergo 

 ecdysis. 



Habitat. — ^The intestine of the goat, sheep, etc. 

 Pathogenicity. — Produces anaemia, resembling that of ankylo- 

 stomiasis, and has a hsemolytic toxin. 



