Hamingia. 



1. Shape of body elongate, cylindrical, 

 tapering towards anus. 



2. Frontal hood (so-called proboscis) as 

 long as body when stretched, tapering to- 

 wards the free end, narrow and trough- 

 like. 



3. Uteri and female genital pores one 

 or two, each opening on a well-marked pa- 

 pilla. 



4. Male exceedingly minute, parasitic 

 on female. 



5. Genital setfB absent in the female, 

 present posteriorly to the genital pore in 

 the diminutive male. 



6. Ova enclosed in a capsule of u folli- 

 cle-cells " with a mass oi nutrient cells 

 attached. 



7. Mature ovum divisible into an outer 

 "nutrient" zone of vacuolated protoplasm 

 and an inner denser protoplasm. 



8. Uterine pouch or pouches when filled 

 with eggs have delicate hyaline walls. 



9. Internal opening of uterine pouch a 

 plicated funnel with ciliated surface. 



10. Anterior portion of pharynx dilated. 



11. Cloacal nephridia divided into lobes 

 or branches ; nephrostomes mounted on 

 long stalks. 



12. Corpuscles of the perivisceral fluid 

 coloured red by haemoglobin. 



Thalassema. 



1. Same as Hamingia. 



2. Same as Hamingia. 



BONELLIA. 



1. Shape of body subspherical, de- 

 pressed on neural face. 



2. Frontal hood much longer than the 

 body, having a narrow trough-like stalk 

 and a widely expanded caryophyllaceous 



3; Uteri and female genital pores four 

 or six, not opening on papillae. 



anterior region. 



3. Uterus and female genital pore single 

 not opening on a papilla. 



* 



4. Males and females alike in size and 4. As in Hamingia. 



colour. 



5. A pair of strong genital setaa in both 

 male ana female in front of the genital 

 pores in both male and female. 



6. Ova not enclosed in follicle-cells (at 

 any rate in T. neptuni !) ; nutrient cells 

 attached. 



5. A pair of strong genital setse in the 

 female in front of the single genital pore ; 

 absent in the male of B. viridis and pre- 

 sent as in Hamingia in B. minor. 



6. Ova as in Hamingia. 



7. Mature ovum more nearly homo- 7. Mature ovum as in Hamingia. 



geneous. 



8. Uterine pouches even when distended 

 have firm resistant walls. 



9. As in Hamingia , except in some 

 species, w T here it is drawn out into a long 

 spiral trough. 



10. Anterior portion of pharynx not 

 dilated. 



11. Cloacal nephridia simple sacs; ne- 

 phrostomes on short stalks. 



12. Same as in Hamingia in one species 

 (T. neptuni) ; probably not so in others. 



8. Wall of uterine pouch very solid. 



9. Internal opening of uterine pouch 

 firm, like the mouth and neck of a bottle. 



10. As in Hamingia. 



11. As in Hamingia. 



12. Perivisceral fluid colourless 





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