BY S. J. JOHNSTON. 345 



eggs, and in the spininess of the body, continued with hardly any 

 diminution to the extreme posterior end of the body. 



Pleurogenks solus, sp.n. 

 (Figure 17.) 



Diagnosis. — Body oval, narrower at the anterior end, 0"815mm. 

 long, by 0-49 mm. broad; oral sucker subterminal, O'lll mm. in 

 diameter, ventral sucker behind the middle of the body, 0' 121 mm. 

 in diameter; ratio of oral to ventral sucker, 11 : 1 2. Skin spiny. 

 Pharvnx very well developed, globular, O'Ool mm. in diameter; 

 oesophagus with the intestinal limbs reaching to the anterior edge 

 of the ventral sucker. Excretory vesicle large, V-shaped, pore 

 terminal. Testes small (U'098 mm. in diameter), round, symme- 

 trically placed on either side of the ventral sucker; ovary oval 

 (0-098 X 0049 mm.), in front of and slightly internal to the right 

 testis. Cirrus-sac large, 0*245 mm. long, S-shaped, entirely in 

 front of ventral sucker; genital opening on a level with the 

 pharynx. Vitelline glands oval or pear-shaped, large (O'OoS x 

 0-028 tnm. ), fetv ( nine on each side). Coils of the uterus as in P. 

 freycineti, without a second loop crossing from one side to the 

 other. Eggs yellow, elliptical, very small, 0-020 x O'OIO mm. 



Host, Hyla aurea, in the intestine. 



Type-specimen in the Australian Museum, Sydney, No. W. 345. 



This little species was found in the intestine of Hyla aurea, 

 along with a large number of specimens of Dolichosaccus. Out of 

 the hundreds of this kind of frog examined, only one single speci- 

 men of Pleuroyenes was found. This specimen was fixed in 

 sublimate acetic, kept flat by the vaseline-method, stained with 

 borax-carmine, and mounted whole. It is obviously a distinct 

 species from Pleurogenes freycineti, with such well-marked specific 

 characters as, (i.) an entirely different relation in the size of the 

 suckers, the ventral being larger in P. solus, while in P. freycineti 

 it is the oral sucker which is larger than the ventral; (ii.) the 

 comparatively longer intestinal limbs in P. solus; (iii.) the very 

 much smaller gonads; (iv.) the more posterior position of the 

 testes in relation to the ventral sucker; (v.) the more posterior 

 position of the genital aperture; and (vi.) the smaller eggs. 



