306 THE CHICAGO ACADEMY OF SCIENCES. 



round, of equal diameter throughout; vas deferens 15.00 mill, long; 

 penis retractor very long and very narrow; penis-sac retractor very 

 long, wide, ribbon-like; penis-sac protractors usually six in number, 

 three anterior and three posterior. The anterior protractors are 

 largest and are frequently fused ; prostate duct 5.00 mill, long, slightly 

 enlarging as it enters the prostate ; prostate flattened, much elongated, 

 rounded at either end, the larger end receiving the prostate duct; the 

 prostate gradually tapers to the narrow portion which joins the uterine 

 portion of the oviduct. 



Female organs : Receptaculum seminis large, pear-shaped, con- 

 nected with the oviduct by a duct 7.00 mill, long, which enters the 

 oviduct 1.25 mill, from the vaginal opening; the first accessory albu- 

 miniparous gland is very elongate-ovate, narrowing suddenly at both 

 ends; it is markedly creased in the center, longitudinally, where the 

 prostate is attached ; second albuminiparous gland very small, rounded ; 

 albuminiparous gland not differing from those already described; the 

 lower portion of the oviduct is long and very narrow. 



The organs are colored as follows: Penis-sac, blackish; penis, 

 yellowish flesh ; prostate, flesh ; receptaculum seminis, yellowish ; albu- 

 miniparous glands, yellowish. The musculature of the penis-sac varies 

 considerably. The posterior protractors may be one or four in number, 

 while the anterior protractors vary in number and in position. There 

 are several very small muscles close to the penial opening, which vary 

 in number. In specimens from Florissant, Colorado, the posterior 

 protractor muscles varied in number from two to four, while the 

 anterior protractors were almost invariably a constant of four. (PI. 

 XV, fig. C.) In one specimen (C, 3) the penis retractor had a small 

 branch extending to a point in the penis-sac just above the penis-sac 

 retractor. In another specimen (C, 1) the two retractors were joined 

 as they entered the columellar muscle. 



The comparative measurements of the genitalia of several indi- 

 viduals are as follows (dissections Nos. 23454 to 23457, 23500, 23596) : 



