Diaptomus Pseudosanguineus Sp. Nov. 5 



COPEPODA 

 FAMILY CENTROPAGIDAE 

 GENUS DIAPTOMUS WESTWOOU 



1. DIAPTOMUS ASHLANDI Marsh 1893. 



Diaptomus anhlundi. Marsh, '93. p. 198. pi. 3, f\g. 11-13. 

 Diaptomus aahlandi, Herrick & Turner, '95. p. 60. pi. 6, fig. 4-6. 

 Diaptomus ashlandi, Schacht, '97. pp. 167-169. pi. 32, fig. 1-4. 

 Common. Kound in lakes, no-outlet ponds and marshes, through a 

 temperature range of 15-35°C. Usually abundant. 



2. DIAPTOMUS OREGONENSIS, Lllljeborg 1889. 



Diaptomus oregonensis, Herrick & Turner, '95. pp. 72, 73. pi. 4, 



fig. 7-12 ; pi. 9, fig. 3. 

 Diaptornus oregonensis. Schacht, '97. pp. 151-154, pi. 29, fig. 1, 2. 

 Found three times in this district in no-outlet ponds ; in one case col- 

 lected from the midst of vegetation ; in the other two cases the ponds con- 

 tained no higher plants. The temperature of the water ranged from 15- 

 20°C. The F'H value ranged from 7.6 to 8.2. Abundant in each case. 



3. DIAPTOMUS PAL.L.IDUS Herrick 1879. 



Diaptomus pallidxts, Herrick & Turner, '95. pp. 73, 74. pi. 4, flg. 



1-6 ; pi. 5, fig. 10 ; pi. 13, fig. 17. 

 Diaptoynus pallidus, Schacht, '97. pp. 144-146. pi. 27, fig. 3. 

 Encountered in this region but once, in June, 1920, when it waa abund- 

 ant in a no-outlet pasture pond. 



4. DIAPTOMUS PSEUDOSANGUINEUS, sp. nov. (pi. 1-3). 

 For description consult the first section of this paper. 



5. DIAPTOMUS SANGUINEUS Forbes 1876. 



Diaptomus sanguineus, Forbes, '76. pp. 15, 16, 23. fig. 24, 28-30. 

 Diaptoynus sanguineus, Herrick & Turner, '95. p. 71. pi. 13, fig. 12. 

 Diaptomus sanguineus, Schacht, '97. pp. 133-137. pi. 23-25. 

 Collected but once in this district, in a no-outlet pond in 1909. 



6. DIAPTOMUS SICILIS Forbes 1882. 



Diaptomus sicilis, Herrick & Turner, '95. pp. 60, 61. pi. 5, flg. 1-7 ; 



pi. 13, fig. 18. 

 Diaptomus sicilis, Schacht, '97. pp. 122-124. pi. 21, fig. 1-3. 

 Found in April, 1909, in large numbers in the open waters of a large 

 lake, the temperature of which was 11°C. The water was free from vege- 

 tation and there were practically no algae. The altitude of the lake is 440 

 feet. Not found since although frequent collections have been made In the 

 same part of the lake. 

 7. DIAPTOMUS STAGNAL/IS Forbes 1882. 



Diaptomus stagnalis, Forbes. '82. pp. 15, 16, 23. fig. 24, 28-30. 

 Diaptomus stagnalis, Herrick & Turner, "95. pp. 71, 72. pi. 13, tig. 



8-10. 

 Diaptomus stagnalis. Schacht, '97. pp. 138-141. pi. 28. fig. 2. 

 Found in this district only once, in June, 1920, in a shallow, no-outlet 

 pond free from vegetation. 



FAMILY CYCLOPIDAE 

 GENUS CYCLOPS O. F. MUELLER 

 8. CYCLOPS ALBIDUS Jurine 1820, var. tenuicornis Sars 1863. 



Cyclops aignatus, var. tenuicornis, Herrick & Turner, '95. pp. 106, 



107. pi. 15, fig. 5-7; pi. 20, fig. 1-7; pi. 33, fig. 1, 2. 



Cyclops albidus. E. B. Forbes, '97. pp. 47-49. pi. 13. 



A species widely distributed in this district, in marshes, small temporary 



pond.s, small no-outlet ponds, and lakes. It is found where vegetation does 



and does not exist, occurring in water ranging from 10''-25''C. and having 



PH values ranging from 7.2 to 8.0. In some specimens the hyaline plate 



