12 PROCEEDINGS OF THE NATIONAL MUSEUM vol.70 



constricted rather uniformly near the scolex, several incipient 

 proglottides being included in the bead-like portion included 

 between two adjacent constrictions. 

 1913, August 5. — Five strobiles, 3 with scoleces, about 30 mm. 

 in leng-th and 1 mm, in breadth ; also 3 very small scoleces and 

 fragments of both larger and smaller strobiles. 

 U. S. N. M., Helm, Coll. 7862. 

 Puflmas gravis^ new host: 



1904, October 31. — Eight strobiles with scoleces, and about 25 

 without scoleces ; maximum length, in alcohol, 70 mm. 

 Puffinus griseus, new host : 



1906, June 8, — Six birds examined by Mr. Edwards; few ces- 

 todes; gi-eat difference in size, but most of them large. Di- 

 mensions of one, in formalin: Length 80 mm.; greatest 

 breadth 2.5, thickness 1.5. 

 1906, June 11. — Six birds examined; cestodes of smaller size 

 than those collected on June 8. 

 Nycticorax nycticarax naevius, new host : 



1913, July 5. — One small strobile, macerated, and a few frag- 

 ments, longest 16 mm. 

 1913, July 5. — One small strobile, macerated, and a few frag- 

 ments, longest 16 mm.. 



Transverse sections were made of the largest fragments. 

 In details of structure of the genital cloaca, cirrus, cirrus- 

 pouch, and vagina, which are satisfactorily shown in the sec- 

 tions, likewise in the musculature, there appears to be exact 

 agreement with corresponding features in the shearwater 

 material. The vralls of the excretory vessels are thick, as in 

 the species from the shearwater, and contain conspicuous lon- 

 gitudinal fibers. The latter do not appear in sections of 

 shearwater material. The difference in this respect may be 

 due to the somewhat macerated condition of the material from 

 the night heron. 



An average of ten cirrus-pouches gives the dimensions: 

 0.045 by 0.055 mm. ; the smallest 0.041 by 0.054, and the largest 

 0.054 by 0.054. 



The maximum number of muscle fibers appears to be about 



20 in the inner bundles and 7 in the outer. The uterus is 



lobed. The proglottides sectioned Avere about 0.08 mm. in 



length and 1.26 mm. in breadth. 



1913, August 5. — Fragments of strobile, longest 40 mm., no 



scolex. 



