10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6l 



The fifth foot of the female (pi. 2, fig. 9) is like that of D. gatunen- 

 sis except that the endopodite is more slender and longer, being two- 

 thirds the length of the first segment of the exopodite. 



The spines of the first basal segments of the fifth feet of the male 

 (pi. 2, fig. 6) are acnte on a prominent mammilliform base. The sec- 

 ond basal segment of the right foot is longer than wide, and has a 

 conical projection on its caudal surface. The lateral hair is situated 

 at four-fifths of its length. The first segment of the exopodite is twice 

 as long as wide, its distal angles are prolonged into blunt, rounded 

 projections, and near the inner distal angle it has on the caudal sur- 

 face a curved cuticular ridge. The second segment is considerably 

 shorter than the combined length of the first segment and the second 

 basal segment, is approximately oval in outline, its greatest width 

 being about two-thirds its length. The lateral spine is situated near 

 the end of the segment, is stout and straight, finely denticulate on the 

 margin, and less than one-half the length of the seg'ment. The ter- 

 minal hook is falciform in its general shape, but with the tip recurved, 

 is denticulate on the inner margin, and is considerably less in length 

 than the combined length of the rest of the exopodite and the second 

 basal segment. The endopodite is rudimentary, being a triangular 

 projection armed with short setae on the inner margin. 



The left fifth foot of the male is like .the corresponding foot in 

 D. gatuiiciisis. 



Length of female 1.581 mm. Length of male 1.362 mm. 



This was found in a collection made by Meek and Hildebrand near 

 Lion Hill, C. Z. 



It will be noticed that D. honinicoUinus is somewhat larger than D. 

 gatuncnsis. The principal distinctive points, however, are in the 

 structure of the fifth feet. These differences in a genus like Diap- 

 tomus, which shows so little variation in specific characteristics, are 

 amply sufficient for the establishment of the species. 



DIAPTOMUS MARSHI Juday 

 1913. Diaptomus marslii Juday. p. 804, figs. 1 and 2. 



A small species. The first cephalothoracic segment (pi. 3. fig. 5) 

 is about as long as the combined length of the three following seg- 

 ments. The last cephalothoracic segment is armed on each side with 

 two rather blunt spines. 



The first segment of the female abdomen (pi. 3, fig. 4) considerably 

 exceeds in length the rest of the abdomen including the furca ; it is 

 dilated in front and bears upon each side a small blunt spine. The 



