190 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loi 



other localities have failed to yield specimens of this species suggesting 

 that its range coincides with that of the molluscan intermediate host. 

 Gonspicuutn macrorchis is closely related to G. icteridorum, but may 

 be easily distinguished from it by its larger and decidedly more 

 muscular body, its more extensively developed vitellaria and uterus 

 and its conspicuously larger testes. 



Genus ZONORCHIS Travassos, 1944 



ZONORCHIS ALVEYI (Martin and Gee, 1949), new combination 



FiGUEE 39, d, e 



Eurytrema alveyi Martin and Gee, Journ. Parasitol., vol. 35, pp. 61-(J6, 2 I 

 figs., 1949. 



The material in the present collection, consisting of 48 mature 

 specimens, agrees very closely with that recently described as Eury- 

 trema alveyi by Martin and Gee (1949) in size and arrangement of! 

 internal organs. Our largest specimens are slightly longer than the 

 original material; they measure 5.42 mm. in length. The "small 

 protuberances" reported on the cuticula of the anterior body region 

 of the type material are conical, retractile, sensory papillae, and are 

 not to be confused with the tuberculations on the cuticle of Brachyle- 

 cithuin rarum and B. tuberculatum. The acetabulum (fig. 39, e), 

 which is strongly muscular, with a deep cup-shaped lumen, is situated I 

 at the junction of the anterior and middle body-thirds. The ratio of i 

 the diameter of the oral sucker to acetabulum varies from 1 : 1.3 to 

 1 : 1.5. Not stressed in the original description is the characteristic 

 manner in which the ceca pass dorsal to the medial margins of the 

 testes, forcing these organs against the lateral body walls. The ceca 

 continue posteriorly some distance beyond the testes, medially to the 

 vitellaria. The ovary, which is shallowly but distinctly lobed in all 

 of our specimens, lies slightly to the left of the midline as often as 

 to the right of that line. The uterus, which fills most of the post- 

 acetabular region of the body, forms characteristic anteriorly directed 

 loops between the acetabulum and testes before ascending to the genital 

 pore by a slightly wavy course. 



Although the complete excretory system could not be worked outi 

 from our specimens, sufficient details could be seen to indicate that 

 the system differs from that described for the type material. In our 

 material the common collecting tubules pass anteriorly and laterally, 

 dorsal to the medial margins of the testes, to bifurcate into anterior 

 and posterior main collecting tubules at the level of the equator of 

 the acetabulum (or dorsal to anterior margins of testes). Each of ^ 

 the anterior main collecting tubules gives rise to three accessory 

 tubules which branch almost immediately into dorsal and ventral 



