Diaptomus Pseudosanguineus Sp. Nov. 25 



Marsh, C. Dwight, ('18). Copepoda. Fresh-water Biology, by Henry 



B. Ward and George C. Whipple, pp. 741-789. 1918. 

 Schacht, F. W. ('97). The North American species of Diaptomus. 



Bull. 111. State Lab. of Nat. Hist. 5:97-207. pi. 21-35. 1897. 

 Turner, C. H. ('10). Ecological notes on the Copepoda and Cladocera 



of Augusta, Ga., with descriptions of new species. Trans. Acad. 



Sci. St. Louis 19:151-176. pi. 36-38. 1910. 



Explanation of Plates 



PLATE I. 



Pig. 1. Diaptomus pscudosanguincous, sp. nov., ventral view of 

 female; c, tubercles on the distal margin of the thorax; d, strong 

 curved spine on the lateroventral portion of the first segment of the 

 abdomen. 



Fig. 2. Diaptomus pscudosanguincous, sp. nov., lateral view of 

 male. 



Fig. 3 Lateral view of the female; j, spermatophore. 



Fig. 4. Antenna of the female. 



PLATE II. 



Fig. 1. Lateral view of female illustrating a case of commensal- 

 ism between this form and certain Vorticellidae; e, one of the com- 

 mensal Vorticellidae. By examining that portion of the illustration 

 labeled e with a magnifying glass the protozoan will be distinct. The 

 use of the glass will also reveal retracted Vorticellidae among the 

 eggs. 



Fig. 2. Caudal extremity of the thorax and the first abdominal 

 somite of a female (lateral view); f, stout curved spine; g, sperma- 

 tophore. 



Fig. 3. Antipenultimate segment of the male right antenna; h, 

 terminal claw; i, hyaline flange. 



PLATE III. 



Fig. 1. Fifth foot of the male; a, endopodite of the left fifth foot. 



Fig. 2. Antennae of the male. 



Fig. 3. Pair in copulo. 



Fig. 4. Enlarged view showing the tubercles on the caudal mar- 

 gin of the thorax; b, the tubercles. 



Fig. 5. Fifth foot of the female. The terminal setae moved re- 

 flexly, while the photo was being taken, thus causing the appendage 

 to appear to have several terminal setae. There are only two long 

 setae at that place. 



PLATE IV. 



Fig. 1. Ccriodaphnia rigaudi, shell markings. 



Fig. 2. Ccriodaphnia rigaudi. Female, b, antennae c, beak-like 

 projection from head. 



Fig. 3. Moina brachiata, female, showing commensalism; a, Voitl- 

 cellidae. 



Fig. 4. Pleuroxus ham-ulatus. 



Fig. 5. Ccriod/iphnia laticaudata. 



Fig. 6. Ccriodaphnia rigaudi, female, showing the escape of a 

 young specimen from the brood sac. By turning the page sidewise 

 the details of this photo become more distinct. 



