ART. 7 CESTODE PAEASITES OF BIRDS LINTON 45 



From Fulica americana^ new host. The ripe proglottides, in all 

 cases, were much broader than long. Thus, in a fragment of strobile, 

 in which all the proglottides are filled with the relatively large ova, 

 and the septa between the proglottides are not distinguishable, the 

 length of a single proglottis was 0,07 mm. and the breadth 0.70. 

 The cirri were nearly cylindrical, 0.09 to 0.10 in length, 0.012 in diam- 

 eter at base, and 0.015 near the tip, whence they tapered to a short, 

 acute to acuminate, point. They were spinous except at the tip. The 

 largest fragment is about 12 mm. in length. There are a few imma- 

 ture strobiles which appear to belong to this species. One of these, 

 about 3.5 mm. in length, is lanceolate; diameter of scolex 0.18; stro- 

 bile increasing in breadth gradually from about 0.10 to a maximum 

 of 0.28, which is at a point 0.4 from the posterior end. The segments 

 are short, nowhere more than 0,015 in length, until near the posterior 

 end; penultimate segment, length 0.045, breadth 0.126; posterior seg- 

 ment, length 0.06, breadth 0.105. The length of the hooks on all 

 the scoleces but one was about 0.033; on one they were about 0.029 

 in length. 



From Mergus serrator^ new host. A few short fragments, the an- 

 terior ends of strobiles, maximum length 4 mm. Length of hooks 

 0.036 mm.; cirri spinose, somewhat clavate, bluntly rounded and 

 smooth at the apex; breadth of scolex 0,15 to 0.20, 



From Oideviia deglandi^ new host. Length of hooks 0.033 mm. 

 Cirri, when fully exserted and not collapsed, usually about 0,12 in 

 length, with a diameter of from 0,012 to 0,018; but in one strobile 

 the maxinuim length of a cirrus was 0.16 and the maximum diameter 

 0.033. Where best seen the cirrus is characterized by having a cylin- 

 drical base covered with minute spines which are less crowded dis- 

 tally where the cirrus becomes slightly swollen ; beyond this point it 

 is usually clavate, with slender spines which become shorter toward 

 the tip, where the}'^ are very minute. The anatomy of a proglottis, 

 as shown in sections, agrees with the foregoing. The ovary in some 

 transverse sections was dumb-bell shape, and was composed of dis- 

 tinct, subangular cells. The dorsal and ventral excretory vessels lie 

 close together, and the cirrus-pouch and vagina pass on the dorsal 

 side of the poral pair. The musculature was not well shown in the 

 sections. There appeared to be but a small number of longitudinal 

 muscle bundles. 



From Oiderma perspicillata.f new host. Strobiles all small and 

 immature, agreeing with immature strobiles from O. deglandi. 

 There is a tendency to assume a slightly fusiform shape. At the 

 posterior end there is usually a longer or shorter portion where the 

 proglottides are moniliform. Length of hooks 0.036 mm. 



