P. Manson-Bahr and N. H. Fairley 
71 
PLATE IV. 
Fig. 1. Laige Pigmented Cercaria of Gastrodiscus aegyptius (Cobbold), Gastrothylux gregarius 
(Looss), or of Amphistomum, conicum (Rud). The former is a parasite of the horse, the latter 
two of the buffalo. Looss followed the development of the former, in Cleopatra bulimoides, and 
of the latter two, in his Physa alexandrina (Bourg) now known as Bullinus contortus. Highly 
pigmented forms, which he figures as Cercariae of Amphistomum conicum-, were found asso¬ 
ciated in the liver of the same snail, with hyaline Cercariae, with pigmented ocular spots, which 
he describes as Cercariae of Gastrodiscus aegyptius. 
Total length 0-845 mm. Body 0-474 mm. x 0-427 mm. 
Tail 0-40 mm. Form cysts as in 14. 
These Cercariae have been found in Bullinus contortus, Planorbis boissyi, Limnaea caillaudi. 
and Cleopatra bulimoides. 1 % Planorbis, 5 % Bullinus naturally infested. 
Fig. 2. Mature redia of 16, showing the anteriorly situated sucker, alimentary canal, germiniferous 
cells at the posterior end, the numbers of young Cercariae. Size 0-777 mm. x 0-135 mm. 
Fig. 3. Cercaria pleurolophocerca (Sonsino) found in the majority of specimens of Melania tuber- 
culata, from the Zoological Gardens, Cairo. Very striking Cercaria; tail with cuticular caudal 
expansion. 
Total length l.-O mm. Body 0-27 mm. x 0-08 mm. Tail 0-49 mm. 
All Ceiouiiae and Rediae measured, and figured in these plates, have been derived from fresh 
dissections, and were killed in water by heat. 
1 ig. 4. Cercaria from liver of Cleopatra bulimoides. 
Total length 0-807 mm. Body 0-5 mm. x 0-135 mm. Tail 0-300 mm. 
(Cercaria distomatosa.) Sonsino. 
Note the bifid character of the extremity of the tail. 
Fig. 5. Cercaria commonly found in Planorbis, Bullinus and Physa (31 % of Bullinus naturally 
infested, and 2 % of Planorbis), not described by Looss. 
Total length 0-76 mm. Body 0-382 mm x 0-125 mm. Tail 0-387 mm. 
kig. 6. Encysted Cercaria same as 13—commonly found in liver of Bullinus, especially 
during the winter months. Average diameter 0-165. 
Fig. 7. Orange-pigmented Redia of 13. Length 1-43 mm. x 0-143 mm., showing muscular 
terminal sucker, rudimentary alimentary canal, and contained Cercariae in various stages 
of development, also lateral appendix. 
PLATE V. 
Figs. 1' and 2. See legend on plate. 
