672 ^^ • G- MacCallum, 



The ovaij is situated ratlier toward tlie ventral surface beliind 

 the testes and a little to the right. It measures about 0,26 mm in 

 diameter and is ronnded or pear-sliai)ed. Dorsallj' it g-ives off a 

 Short oviduct which is quickl}^ joined by the tliick-walled , narrow 

 Laurer's canal which opens as stated above in the midline dorsally. 

 The tnbe produced by their union passes into a mass of large cells 

 with larg-e vesicular nuclei, a tissue which is doubtless to be inter- 

 preted as a shell g:land. There it is joined by the wide canals 

 which lead on each side from the iaterally placed vitellarium and 

 from this point there begins the canal, at first thick-walled and 

 narrow, later quite wide and thin-walled which is the Uterus. The 

 Uterus shows great Variation in width and in the thickness of its 

 walls. for while some convolutions are packed with eggs and granulär 

 or filamentous material there are other portions which are empty 

 and contracted so that the wall is quite thick. The convolutions 

 are most tortuous in the posterior part of the body behind the testes 

 and there most of the eg-gs are to be seen. The eggs are elliptical. 

 quite smooth, and thin-walled, and measure about 0,145X0,080 mm. 

 They are usually present in ratlier small number. The vitellarium 

 consists of lateral lobulated masses which extend on each side from 

 the level of the bifurcation of the intestine to the end of its coeca. 

 For the most part, the lobules contain large clear cells with 

 relatively small, darkly-staining nucleus, but in the portions im- 

 mediately about the transverse ducts, the cells become filled with 

 large granules. The uterus passes forward dorsal to the testes to 

 open also at the termination of the papilla in the genital cloaca 

 posterior to the opening of the ejaculatory duct. The terminal 

 portion is lined by cuticle. 



Of Diesing's forms only Amphistoma oxijcephalum from Salmo and 

 Silurus and Ä. cylindricum from CaJUchiliys are at all similar to this. 

 It is true that both of these are also parasites in tlie intestines of 

 Siluroid fishes in fresh water tropical streams, but while they were 

 coUected in Brazil the other form was found in Sumatra. 

 His descriptions are briefly as foUows: 



A. oxyceplialum. A. corpore polymorpho, planiuscnlo, comprcsso 

 mit fereti, ohlongo ovafo, aut ovafo lanccolato, ore tcrminali orhmdari; 

 acetahidi sudorii lateralis orhicidaris Jiinc postice sinuati limho promimdo. 

 The worm varies in size and form, measuring 2 — 6 lines (4.5 — 13.5 mm) 

 by 1 — 3 lines (2.25 — 6,75 mm). The body flat or compressed, long- 

 oval or lanceolate. brownish or white. A network is often seen in 



