GASTRODISCUS HO MINIS 



563 



anterior border, where it becomes thick and muscular, and is called the 

 'metatrema.' The eggs are large (122 to 130 jj, in length by 75 to 80 /ll in 

 breadth). , 



Life-History. — -The life-cycle is not known, but it is believed that 

 the usual host is a herbivorous animal. 



Pathogenicity.— It may perhaps cause diarrhoea and anaemia. A 

 post-mortem showed the mucosa slightly congested. 



Diagnosis. — By recognition of the eggs or adults in the faeces. 



Treatment.— The eucalyptus and chloroform mixture advised for 

 ankylostomiasis (Chapter LXXV.). 



Family II. Gastrodiscid^ Stiles and Goldberger, 1910. 



Definition. — ^Paramphistomoidea with rather discoidal bodies 

 divided by a transverse constriction into cephalic and caudal 

 portions. Ventral pouch absent. Venter with many large papillae. 

 Acetabulum ventral at caudal end. 



Type Germs— Gastrodiscus Leuckart, 1877; the other genus is 

 Homalogaster Poirier, 1883. 



Gastrodiscus Leuckart, 1877. 



Definition. — Gastrodiscidae with bodies slender anteriorly and 

 broadened posteriorly. The latter contains the genital glands. 

 The acetabulum is small. The ventral pouch is absent. The oral 

 sucker has paired evaginations, and leads into an oesophagus with 

 muscular thickening. The caeca are long, not wavy, and end post- 

 testicalarly. Male organs These are two branched testes, and 

 a cirrus pouch which is not completely closed. Female organs:' — ■ 

 Ovary and shell gland are post-testicular ; vitellaria are extracaecal; 

 and the uterus intercaecal. Laurer's canal is pre vesicular. 



Type. — Gastrodiscus cBgyptiacus Cobbold, 1876, in the horse. 



Other Species. — G.hominis in man;G. secundus Looss, 1907, in 

 the horse; G. minor Leiper, 1913, in the pig in Uganda and Nigeria. 



Gastrodiscus hominis Lewis and McConnell, 1876. 



Synonym.^ — -Amphistomum hominis Lewis and McConnell. 



Definition. — Gastrodiscus 5-8 mm. in length and 3-4 mm. broad. 



History. — It was first described in 1876 by Lewis and McConnell, 

 who found it in hundreds attached by its posterior sucker to the 

 mucosa of the caecum, vermiform appendix, and ascending colon of 

 an Assamese. Since then it has been reported in natives of India, 

 and perhaps it may be common. We have not met with it in 

 Ceylon, though there was a small jar in the Medical College Museum 

 labelled Amphistomum hominis, but without a history. 



Leiper has made G. hominis the type of a new genus Gastrodiscoides, distin- 

 guished from Gastrodiscus by the absence of papillae on the venter and the 

 position of the genital pore on the cone. 



Morphology. — The parasite is reddish-coloured, 8 to 10 millimetres in length 

 and 4 to 5 millimetres in greatest breadth, tapering to 2-5 millimetres in front. 

 The thickness is about 4 millimetres. The posterior end of the body presents 



