ART. 8. ON BOECKELLA AND PSEUDOBOECKELLA MARSH. 25 



slightly recurved at the tip. The terminal segments of the exopodites 

 have 6 spines. 



Male. — In the fifth feet the second basal segment of the right foot 

 in addition to the spine at the outer distal angle has a 2-pointed 

 spine at the inner distal angle. The right endopodite is 1 segmented, 

 exceeds the first segment of the exopodite in length, has 2 stout 

 curved spines at the inner distal angle and upon the tip and extend- 

 ing along the inner side 5 shorter stout curved spines. There is also 

 a straight acute spine near the proximal end on the inner margin. 

 The left endopodite in Scott's figure does not seem to be separated 

 from the second basal segment; it is 1 segmented or perhaps rudimen- 

 tary. Figure 35 shows the fifth feet of the male. 



Length. — Female, 1.6 mm. 



Falkland Islands. 



Fig. 35.— PSEUDOBOECKELLA VALLEN-TINI SCOTT, FIFTH FEET OF MALE, AFTER SCOTT. 



DISTRIBUTION OF THE SPECIES OF BOECKELLA AND 

 PSEUDOBOECKELLA. 



The distribution of the fresh-water Centropagidae is a matter of 

 a good deal of interest, as they are much more restricted in their 

 habitats than some other forms of the Copepoda; for example, many 

 of the species of the Cyclopidae are world-wide in their distribu- 

 tion while many of the species of the Centropagidae are found only 

 over somewhat limited areas. The morphological differences, due 

 to environment, make it possible in the case of the species of the 

 Centropagidae to make some conjectures in regard to their phylogeny. 



Both Boeckella and Pseudohoeckella are genera of the southern 

 continents. Only one species, B. orientalis, is found north of the 



