12 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.64. 



ment of the exopodite. The left endopodite is 1 segmented and less 

 than one-half the first segment of the exopodite. The second seg- 

 ment of the right exopodite bears on the inner surface near the 

 distal end a rather prominent tubercle. Figure 15 shows the fifth 

 feet of the male. 



Length. — Female, 1.505 mm.; male, 1.43 mm. 



Lake Titicaca and Lake Poopo. 



BOECKELLA OKIENTALIS Sars. 



1903. Boeckella orientalis Sars, pp. 196-197, pi. 9, figs. 1-15. 

 19056. Boechella orientalis Ekman, p. 602. 



Female. — ^The first antennae reach the furca. The last cephalo- 

 thoracic segment is produced backward on the sides beyond the first 

 abdominal segment; it has inner lobes, the left one being acute and 

 the right one rounded. The exopodites of the second antennae are 7 

 segmented, the second and seventh segments being long. The termi- 

 nal segments of the exopodites of the fifth feet bear 7 spines. 



Male. — In the fifth feet the right endopodite is 1 segmented, 

 pointed, has a blunt-pointed projection on the inner side near the 

 base, and nearly equals in length the first two segments of the ex- 

 opodite. The left endopodite is 1 segmented, nearly equaling in 

 length one-half the first segment of the exopodite. The second basal 

 segment of the left foot bears on its inner side a serrate lamella which 

 extends distad to the end of the endopodite. Figure 16 shows the 

 fifth feet of the male. 



Length. — Female, 1.7 mm.; male, 1.4 mm. 



Mongolia. 



BOECKELLA POOPOENSIS Marsh. 



1906. Boeckella poopoensis Marsh, pp. 183-187, pi. 17, fig. 5; pi. 18, fig. 2. 



Female, — The first antennae extend to the end of the furcal setae. 

 The sides of the last cephalothoracic segment have inner lobes and 

 project backward the length of the first abdominal segment. The 

 exopodites of the second antennae consist of 5 segments. The termi- 

 nal segments of the exopodites of the fifth feet are armed with 3 

 spines. The third segment of the endopodites of the fifth feet bear 

 5 setae. 



Mxjle. — In the fifth feet each of the second basal segments bears a 

 blunt spine near the inner distal angle. The endopodites are 2 

 segmented; the right reaches one-half the length of the second seg- 

 ment of the exopodite and the left one-half the length of the first 

 segment of the exopodite. Figure 17 shows the fifth feet of the 

 male. 



Length. — Male, 1.4 mm.; female, 1.53 mm. 



Lake Poopo. 



