AUT. 7 CESTODE PABASITES OF BIRDS LINTON 51 



Transverse sections of ripe proglottides agree in detail with figure 

 24 of Ransom's description of R. swvills.^ Longitudinal muscles are 

 but feebly developed, and no circular muscles were seen. 



Although these worms are smaller than the type, and there is, 

 moreover, a crown of hooks on the scolex, which has not been noted 

 in this genus, I prefer, on account of the very close resemblance pre- 

 sented by the anatomy of adult and ripe proglottides, to refer them 

 to R. similis. 



RECORD OF COLLECTION 



Coccyzus americanus : 



1906, June 14. — The taenioids here described were collected from 

 a male yellow-billed cuckoo, found dead on the college cam- 

 pus, Washington, Pa. The stomach contained 20 caterpillars, 

 and jaws and legs of beetles. There were 30 strobiles with 

 scoleces, and many fragments of strobiles, consisting of ripe 

 segments. These fragments vrere of a brick-red color. The 

 worms remained active for some time in normal salt solution. 

 Maximum length, 20 mm. Other dimensions: Breadth of 

 scolex 0.32, of sucker 0.10, of neck 0.20; distance to first 

 segments about 0.30; length of posterior segments 1.12, 

 breadth 0.80. Three ripe proglottides, still attached to each 

 other, had the folloAving dimensions: (1) length 2.72, breadth 

 0.56; (2) length 3.20, breadth 0.64; (3) length 1.60, breadth 

 1. These proportions were changing, due to the contraction 

 and relaxation of the proglottides. 

 (U.S.N.M., Helm. Coll. 7886.) 



DIORCHIS ACUMINATA Clerc 

 Figures 164-173 



Scolex. — Subject to some contraction variations, but in most cases 

 abruptly truncate, with suckers directed forward; rostellum elon- 

 gate, subcylindrical, enlarging at apex, which is surmounted by a 

 crown of 10 hooks. The hooks are characterized by having the long 

 dorsal root slightly curved; length about 0.05 mm. Hooks occur 

 on the suckers, but on account of their small size are not easily seen. 



Strobile. — Slender throughout; proglottides very closely crowded 

 together, beginning as transverse striae a short distance back of the 

 scolex. Rudiments of genitalia appear near the scolex, and develop 

 slowly, although mature male genitalia may appear early; see 

 figure 166, which was sketched from a point less than 1.5 mm. from 

 the scolex. The cirri are slender, armed with straight, bristle-like 



* Bulletin 69, U. S. National Museum, p. 32. 



