52 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 55. 



about 390 \i. in diameter and bears a double crown of 26 to 32 hooks. 

 The large hooks (figs. 52 and 53) are 135 to 175 [x long. The blade is 

 of moderate curvature; the handle is slightly sinuous in outline, fre- 

 quently tapering slightly and with a tendency to turn dorsally at 

 the distal extremity; the guard is somewhat cordiform in lateral 



view, the maximum 

 diameter being a 

 short distance from 

 the union with the 

 blade and handle, 

 and with a projec- 

 tion toward the 

 blade along this line 

 of maximum thick- 

 ness. The small 

 hooks are 78 to 120 [k 

 long. The blade is 

 of strong to mod- 

 erate curvature ; 

 the handle is short, 

 thick, and curved, 

 the convexity of the 

 curve being ventral ; 

 the guard is oval to cordiform and has a median ventral groove. 

 The suckers are large, with a muscular bulb about 300 [x in diameter, 

 but are set close together and are not conspicuous. The neck is dis- 

 tinct, narrow, almost 1 mm. long and may at times have a sharply 

 defined constriction encircling it. The developed strobila may be 

 from 20 to 72 cm. long, with a maximum width of 

 3.5 to 5 mm. and is very thick in the dorso- ventral 

 dimension. Mature segments are wider than long, 

 and are between 1.5 and 2 mm. long, and 2.5 and 3 mm. 

 wide. Gravid segments are longer than wide and may 

 be 6 to 12 mm. long and 3 to 4 mm. wide. The out- 

 line of the strobila is neither serrate nor smooth, but 

 is uneven as a result of transverse furrows of the 

 segments, the normal convexity of the segments and 

 the prominence of the genital papillae. Calcareous 

 corpuscles are extremely abundant, oval in shape, 

 w^ith a maximum diameter of about 20 [x, and are a prominent factor 

 in making the strobila very dense and opaque. In young seg- 

 ments the posterior angles of each segment are considerably pro- 

 longed, but the prolongation extends posteriorly rather than lat- 



FlG. 52. — MULTICEPS SERIALIS. LARGE AND SMALL HOOKS. 



Fig. 53.— Multiceps 

 SERIALIS. Large 

 and small hooks. 

 Enlarged. Af- 

 ter Neumann 

 1S92. 



