646 PROCEEDINGS OF THE XATIOXAL MUSEUM, vol. 40. 



Davainein.e. 



3. One or two rows of hooks on the rostellum Genera Davainea and Cotugnia. 



Three rows of hooks on the rostellum; cortical parenchyma and musculature greatly 



developed; genital pores unilateral; dorsal excretory vessels absent; testi- 

 cles numerous; cirrus pouch 450 /n long, not extending inward as far as the 

 excretory vessels; female glands not median, displaced toward the pore 

 side of the segment; eggs with two or three membranes in addition to an 

 outer parenchymatous envelope; size of strobila 24 to 40 cm. in length by 

 6 to 10 mm. in maximum breadth; recorded as parasitic in Numida ptilo- 

 rhyncha, Africa Porogynia lata. 



Idiogenin^e. 



4. Two rows of hooks on the rostellum 5. 



Ten to twelve rows of hooks (25 to 30 p. long) on the rostellum; retracted rostellum 



in a cavity whose inner surface is thickly covered with spines; suckers 

 unarmed; cortical parenchyma and musculature greatly developed; dorsal 

 excretory vessels absent or very small; genital pores unilateral; sexual 

 canals pass ventral of ventral excretory vessel and nerve; cirrus pouch 

 about 250 /* long not extending inward as far as the excretory vessel; testi- 

 cles numerous; female glands displaced laterally toward the pore side of 

 the medullary parenchyma; eggs with two thin shells; para-uterine organ 

 supplied with rather numerous calcareous corpuscles; strobila 20 to 37 cm. 

 long with a maximum breadth of about 4 mm.; recorded as parasitic in 

 Neotis caffra, Africa Sphyroncotxnia uncinata. 



5. Strobila not over 7 cm. long and not over 2 mm. in maximum breadth; not more 



than 200 hooks on rostellum; suckers unarmed; cortical parenchyma and 

 musculature weakly developed; genital pores unilateral or arranged in 

 alternate series of 8 to 10 on each side of the strobila; cirrus pouch relatively 

 large, crossing the nerve and excretory vessels and extending far into the 

 medullary portion of the segment, and supplied with a retractor muscle; 

 testicles few (less than 20); female glands practically median; eggs pass 



from uterus into an anterior para-uterine organ (Idiogenes) 6. 



Strobila 20 cm. or more in length and over 3 mm. in maximum breadth; more than 

 300 hooks on rostellum; suckers armed; cortical parenchyma and mus- 

 culature greatly developed; genital pores unilateral or alternating; cirrus 

 pouch small, compared to the size of the segment, either not crossing the 

 excretory vessels or extending beyond them only slightly; testicles numer- 

 ous; female glands median or displaced slightly toward the genital pore ; 

 eggs pass anteriorly into a para-uterine organ from the uterus either directly 

 or after the disappearance of the uterine wall and the envelopment of the 

 eggs in individual parenchymatous capsules ( Chapmania) 9. 



Idiogenes. 



6. Genital pores unilateral 7. 



Genital pores arranged alternately in series of 8 to 10 on each side of the strobila; 



strobila 15 to 25 mm. long and 0.3 mm. in maximum breadth; genital cloaca 

 small, funnel shaped; testicles 10 to 15 in number; eggs with three thin 

 shells; recorded as parasitic in Otis tarda, Tetrax tetrax, and Houbara 

 undulata Idiogenes otidis. 



7. Rostellar hooks 150 or more in number, about 10 jx long; length of strobila not over 



3 cm., maximum breadth not over 0.5 mm 8. 



