ART. 14 



NORTH AMERICAN COPEPODS MARSH 



15 



abundant in eastern Nebraska. It occurs as far west as Pueblo, 

 Colo., and as far south as New Orleans. E. Foster has reported to 

 the writer that it is the most common form near New Orleans, oc- 

 curring through the year. The most eastern locations are Ohio, 

 where it was found by Turner, and Alabama; there may be some 

 doubt about the Alabama situation — it is based on a statement by 



Figure 6.— Distribution of Diaptomus oregonensis Lilljeboro (#), D. marshi Judat (+), D. 



TENUICAUDATUS MaRSH, (D), AND D. PISCINAE FORBES (O) 



Herrick that he had found there a form " like pallidus.'''' It is a little 

 strange that it has been found in only one place in Wisconsin, in 

 Heart Lake, Marquette. Its distribution is shown in Figure 8. 



DIAPTOMUS PISCINAE Forbes, 1893 



In the paper by Marsh, 1907, D. piscinae was considered a variety 

 of D. leptopus. Further collections make it probable that the differ- 

 ences which distinguish this from D. leptopus are constant, and it 



