MORPHOLOGY OF CESTODES FROM POULTRY 31 



The scolex is SO/x in breadth and 120jli in length; neck is AOfx in 

 diameter and 30 to 35/* long; suckers are 55 to 60/x in diameter. 

 The rostellum is 60/x long and 20/x in breadth, armed with a crown 

 of 18 hooks arranged in a single row. These hooks (Fig. 9) are 

 30/* long with a long dorsal root and a short ventral root. The 

 suckers are lined with numerous minute booklets or spines 1.5 to 2/* 

 long which extend over the edges of the suckers and also over the 

 greater part of the surface of the scolex, including a part of the 

 neck region. Schmidt (1894: 16) described cuticular booklets on 

 the suckers of Drepanidotmiia anatina. 



The size of the scolex may be somewhat variable as shown by 

 those in the cysticercoids of Drepanidotcunia anatina by Schmidt 

 (1894: 10). In that species the intermediate host could be one of 

 two or more species of crustaceans and the size of the cysticercoid 

 varied with the size of the host in which it was parasitic. 



The head of the rostellum is conical in shape, bearing a bluntly 

 pointed apex anterior to the end of the dorsal roots of the hooks 

 (Fig. 10, r). This part of the rostellum is composed of minute 

 muscle fibers which are both circular and oblique. The rostellum is 

 slightly broader below the circle of hooks as it is an oval shaped 



body. 



The rostellar sac (Fig. 10, rs) is a deeply stained structure 10 

 to I2fi thick. It extends from 10/x below the hindermost part of 

 the rostellum to the anterior extremity of the scolex, forming an 

 oval shaped sac or sheath. It is composed of parenchymatous 

 tissue with large heavily stained oval or spindle shaped cells which 

 bear processes. The outer part of the sac is composed of a thin 

 layer of fine fibers which help to give it a definite shape. At the 

 lower edges of the sac the fil)ers are connected or associated' to 

 some extent with similar fibers that form the inner layer of the 

 suckers. The anterior region of the rostellar sac, which forms 

 the sheath for the free head portions of the rostellum, is constructed 

 of an inner layer of fine fibers and an outer layer of large spindle- 

 shaped cells, the most of which bear fibrous processes at one or 



both ends. 



The suckers are composed of large spindle-shaped cells which 

 are arranged perpendicular to the edge. These are heavily stained 



