no. 1844. CESTODE FROM AFRICAN BUSTARD— RANSOM. 645 



subfamily (Davaineinse) from that in which S. uncinata evidently 

 belongs. Porogynia lata, according to Fuhrmann (1902; 1908; 1909), 

 is a rather large species, reaching a length of 24 to 40 cm. with a maxi- 

 mum breadth of 6 to 10 mm. The suckers apparently are unarmed. 

 The cortical parenchyma of the strobila is very thick and the muscula- 

 ture greatly developed. Dorsal longitudinal excretory vessels are 

 absent. The genital pores are unilateral. The cirrus pouch does 

 not extend inward as far as the lateral nerve. The vas deferens is 

 much coiled without seminal vesicle. The testicles are numerous. 

 The female glands are not median but are located in the medullary 

 perenchyma toward the pore side of the segment, the ovary near the 

 longitudinal excretory vessel and the yolk gland between the ovary 

 and the median line. In all these characters Porogynia lata closely 

 resembles S. uncinata. If Fuhrmann be correct in his original opinion 

 (1902) as to the orientation of the segment, there is another important 

 character in which P. lata resembles S. uncinata, namely, the passing 

 of the sexual canals on the ventral side of the longitudinal excretory 

 vessel and nerve. More recently, however, Fuhrmann (1908, 47) 

 has decided that he was mistaken in his first interpretation, and that 

 the side of the strobila which he originally looked upon as ventral is 

 really the dorsal side. Porogynia lata is furthermore somewhat like 

 S. uncinata in the possession of more than two rows of hooks on the 

 rostellum. These two species are the only ones in the entire family 

 known to possess more than two rows of rostellar hooks, and might 

 on this account be placed together generically, though P. lata possesses 

 only three rows (Fuhrmann, 1908; 1909) whereas S. uncinata has 10 

 to 12 rows. With regard to the uterus Porogynia lata presents 

 characters which preclude the generic association of this form with 

 S. uncinata, unless the present system of classification is materially 

 modified. The uterus of Porogynia lata is described (Fuhrmann, 

 1902) as having very thin walls which early disappear, the eggs 

 becoming inclosed singly in parenchymatous capsules and occupying 

 the entire medullary portion of the segment. No para-uterine organ 

 is developed and on this account the genus Porogynia is excluded 

 from the subfamily Idiogeninre. 



By means of the following key S phyroncotxnia uncinata and the 

 various species of tapeworms which it most closely resembles may be 

 readily distinguished. 



KEY TO THE FAMILY DAVAINEID.E. 



1. Para-uterine organs present in gravid segments (Idiogeninee) 4. 



Para-uterine organs absent 2. 



2. One to three rows of hooks on the rostellum; uterus not persistent, eggs becoming 



inclosed in numerous egg capsules (Davaineinse) 3. 



Two rows of hooks on the rostellum; rostellum very broad; uterus persis- 

 tent Ophryocotylinse 



