ISOPODS OF NORTH AMERICA. 699 



"The first and second pairs of pleopoda are two segmented, slender, 

 and styliform. The second pair appear to be the sexual organs, while 

 the first are to some degree rudimentary. 



" The third pleopod is flattened and somewhat operculiform. 



" The fourth and fifth pleopods are broad, flat, thin, and lie flat 

 upon one another and the last segment of the pleon. They and the 

 preceding are the branchial appendages of the animal. 



"The uropoda have been already described. 



"Color white; eyes black; intestine showing through the shell as a 

 grayish line. 



"Female: Similar in general characters to the male, but with the 

 following differences: Body not more than two and one half times as 

 long as wide. First and second pleopods absent. Perseopods, with 

 flattened plates, forming a brood or egg chamber. 



"Length, 3 to 4 mm. 



"Type.Ko. 22586, U.S.N.M." W. P. HAY." 



128. Genus BRACKENRIDGIA Ulrich. 



Eyes absent. 



Median and antero-lateral lobes of head almost obsolete. Flagellum 

 of second antennae composed of seven articles. Abdomen abruptly 

 narrower than thorax; sixth or terminal segment posteriorly rounded.. 

 Body without longitudinal ribs. 



Right mandible with two appendages back of cutting surface; another 

 fringed appendage on the hind cutting surface. Left mandible with 

 two fringed appendages next to cutting surface. Maxilliped with a 

 palp composed of three articles and with two small projections on the 

 anterior margin. Outer branch of uropods longer than abdomen, 

 conical. Inner branch much smaller, spiny. 



BRACKENRIDGIA CAVERNARUM Ulrich. 



Brackenridgia cavernarum ULRICH, Trans. Amer. Microscopical Soc., XXIII, 

 1902, pp. 90-93, pi. xvr, figs. 1-9. 



Localities. Ezell's Cave and Beaver Cave, near San Marcos, Texas. 



Body oblong-ovate, about three times longer than wide, 1 mm. : 4 

 mm. 



Head wider than long, with the frontal margin almost straight, the 

 median and lateral lobes being almost obsolete. Eyes absent. The 

 first pair of antennae are rudimentary and inconspicuous. The second 

 pair have the first and second articles subequal in length; the third 

 article is a little longer than the second; the fourth is one and a half 



Proc. U. S. Nat. Museum, XXI, 1899, pp. 871-872. Although the types (two or 

 three fragments) are in the U. S. National Museum, they have been so mutilated, 

 through dissection, that I have found it more satisfactory to quote the above. 



