Diaptomus Pseudosa/nguineus Sp. Nov. 3 



much more slender and bears at its outer distal mar^n 

 a broad tooth-like expanse. The second joint is slightly- 

 curved inwards, its distal extremity somewhat wider 

 than its proximal. Near the tip of its outer margin it 

 bears a straight spine which is about two-thirds as long 

 as the somite. At its tip is a stout curved claw which 

 is about the same length as the segment. The first seg- 

 ment of the left fifth foot is about as long as the second 

 and the whole appendage extends to a little beyond the 

 tip of the first segment of the expodite of the right foot. 

 The two segments of the outer ramus (exopodite) are of 

 about the same length; the second bears at its tip one 

 long and one short claw-like spine. The inner ramus 

 (endopodite) is slender and about as long as the outer 

 ramus; is unsegmented; its distal third pronouncedly 

 hairy; and the inner margin of its intermediate third 

 coarsely crenate. The antipenultimate segment of the 

 right male antenna (pi. 1, fig. 2; pi. 2, fig. 3) bears a 

 stout almost opaque curved process composed of the 

 same material as the body of the antenna. This process 

 is a little shorter than the next segment of the antenna. 

 Intimately connected with this process and extending 

 along the whole margin of the antipenultimate segment, 

 is a hyaline flange similar to that of Diaptomus san- 

 guineus Forbes. 



Like the female, the male is of a dirty white or gray 

 color. In the prime of life Diaptomus sanguineus 

 Forbes, so far as my experience goes, is red in color, or 

 marked with red or blue. However, it is not claimed 

 that this color difference is of taxonomic value. In other 

 localities the color scheme may be different for it is well 

 known that color in Entomostraca sometimes varies with 

 environment. Nevertheless, the color described is that 

 of individuals in the prime of life, for numerous speci- 

 mens were found in copulo (pi. 3, fig. 3) and many more 

 with spermataphores attached (pi. 1, fig. 3j ; pi. 2, fig. 2g). 



Habitat. — The specimens were found in a spring-fed 



