40 PROCEEDINGS OF THE NATIONAL MUSEUM vol.70 



breadth 0.15; seventh segment, length 0.12, breadth 0.14; eighth seg- 

 ment, length 0.15, breadth 0.12. 



RECORD OF COLLECTIONS 



Colymhus holhoelli^ new host: 

 (U.S.N.M., Helm. Coll. 7878.) 

 1909, January 27. — The vial contained many small scoleces, 78 



counted. 

 1913, February 12. — Fourteen scoleces; strobiles very small and 



short. 



HYMENOLEPIS PODICIPINA (Szymanski) 

 Figures 131-138 



Scolex. — Small, differing in outline in mounted specimens, but in 

 most cases rather subangular, with the suckers directed forward; 

 rostellum short and stout, length and breadth being about equal. 

 Dimensions in glj'^cerine, somewhat compressed: Breadth 0,21 mm.; 

 diameter of suckers 0.08 ; diameter of rostellum 0.08 ; length of hooks 

 about 0.03. The hooks are rather abruptly recurved and sharp- 

 pointed, 10 in number. 



Strohile. — All of the strobiles in the collection are immature. They 

 are characterized by their linear, thread-like structure, and exceed- 

 ingly short and closely crowded proglottides. In a strobile mounted 

 in balsam, and approximately 36 mm. in length, the diameter of the 

 scolex was 0.18, diameter of neck 0.12; length of segments, 2 mm. 

 back of the scolex, approximately 0.003, breadth 0.18; at middle of 

 strobile length of segments approximately 0.01, breadth 0.48; near 

 posterior end length of segments approximately 0.02, breadth 0.40. 

 At the posterior end the strobile narrows abruptly; the narrowed 

 portion in this case is represented by a single proglottis, length 0.08, 

 breadth 0.18. Rudiments of genitalia appear within 5 mm., or less, 

 of the scolex. The genital pores are unilateral, near, but not quite 

 on the margin, near the anterior end of the proglottis. Cirrus 

 slender, filiform; cirrus-pouch thin-walled, cylindrical, straight, and 

 at right angles to the margin. The three testes are small and near 

 together at the median line. The outer layer of longitudinal muscles 

 consists of a large number of very small bundles, the inner is com- 

 posed of eight bundles, four of which are ventral and four dorsal, 

 and all much larger than those in the outer layer. The ventral excre- 

 tory vessels are much larger than the dorsal ; the latter show rather 

 indistinctly in the sections, and appear to be more sinuous than the 

 ventral vessels. The above description is based on material from 

 Colyrribus miritus. 



