NO. 1105. PROCEEDINGS OF THE NATIONAL MUSEUM. 191 



C. pectinata that the question forces itself upon us whether these dif- 

 ferences can not be considered as subspecific, possibly due to some 

 extent to a difference of conditions found in different hosts and in 

 different countries. I frankly admit that during an examination of a 

 large series of specimens 1 have changed my mind a dozen times in 

 regard to tliis particular species. I am now of the decided opinion, 

 however, that this form should be given specific rank. 



The specimens upon which this description is based were collected 

 at Bowie, Maryland, by Hassall from the cottontail (Lepm Ni/lraticus). 

 The strobila attains 100 to 180 mm. in length and 10 mm. in breadth. 



The head is very small, measuring 0.32 to 0.56 mm. broad; it may or 

 may not be sharply denned from the neck; no rostellum or hooks visible; 

 the suckers are small, measuring 0.12 to 0.28 mm. long by 0.112 to 0.24 

 rnm. broad; the opening of the sucker is directed diagonally forward. 

 The neck is very short or absent, segmentation beginning very early and 

 the proglottids rapidly becoming distinct. The anterior portion varies 

 greatly in shape, according to contraction. The genital anlagen appear 

 rather early; at about 5 to 10 mm. from the head two roundish bodies 

 appear in each segment, one on each side of the median field near the 

 longtndinal canals; these anlagen soon change in form to the pistol- 

 shaped anlagen described for Moniezia; at about 25 mm. from the 

 head the first testicles are visible. The genital pores are double and 

 opposite, and situated in about the middle third of the margin. 



Segments 125 mm. from the head measure 0.56 mm. long by 6.5 mm. 

 broad by 0.48 mm. thick. Male organs: The testicles number about 65 

 to 90; they are confined to the dorsal half of the segment distally of 

 the transverse uterus, and do not extend laterally of the ovaries. The 

 cirrus pouch lies dorsally of the vagina on both sides of the segment; 

 it is long, narrow, and quite indistinct, coloring in carmine much more 

 lightly than the vagina. Female organs: The vagina runs ventrally 

 of the cirrus; it is long and narrow. From the margin of the segment 

 for a distance of about 0.48 mm. it is surrounded by a deeply coloring- 

 layer of cells, and then it is reduced to a thin narrow canal which later 

 swells into the receptaculum seminis. The ovary, shell gland, and 

 vitellogene gland resemble those of Moniezia and C. pectinala and lie 

 1.28 mm. from the lateral margin. The uterus may be double or single; 

 in some segments a single uterine aulage extends across the entire seg- 

 ment, running through the ventral portion of the ovary, and passing 

 to the lateral fields dorsally of the longitudinal canals and nerves; in 

 the majority of segments there are two distinct uterine anlagen, one 

 to each set of female glands. The ventral canal runs about midway 

 between the ovary and the lateral margin; the dorsal canal lies dorso- 

 median of the ventral canal and is bound by a heavy cuticular lining. 

 The longitudinal nerve lies laterally of the ventral canal, and ventrally 

 of the genital ducts, about 0.64 mm. from the lateral margin. 



In the older segments the topography described above is preserved, 



