. Fresh-water biology. Freshwater biology. 700 FRESH-WATER BIOLOGY 48 (24) No rostrum. Cervical sinus present. . 49 49 (65) Head small and depressed. Antennules small. Valves oval or round. No post-anal extension of post-abdomen. Ceriodaphnia Dana 1853 . 50 General form rounded or oval; size small, rarely exceeding i mm. Vertex a rounded or angu- lar projection, usually nearly filled by eye. Valves oval or round to subquadrate, usually ending in a sharp dorsal angle or short spine. Antennules not very freely movable. One abdominal process ordinarily developed. Post-abdomen of various forms, la
. Fresh-water biology. Freshwater biology. 700 FRESH-WATER BIOLOGY 48 (24) No rostrum. Cervical sinus present. . 49 49 (65) Head small and depressed. Antennules small. Valves oval or round. No post-anal extension of post-abdomen. Ceriodaphnia Dana 1853 . 50 General form rounded or oval; size small, rarely exceeding i mm. Vertex a rounded or angu- lar projection, usually nearly filled by eye. Valves oval or round to subquadrate, usually ending in a sharp dorsal angle or short spine. Antennules not very freely movable. One abdominal process ordinarily developed. Post-abdomen of various forms, large. Ephippium triangular, with one egg placed longitudinally. Antennules of $ with long, stout seta, modi- fication of flagellum; first foot with hook and long fiagellum. Free swimming; motion saltatory. 50 (51) Head with a short spine or Ceriodaphnia rigaudi Richard 1894. Valves reticulated. Head produced in front of antennules into a short, conical, sharp-pointed, hornlike process. Two abdominal proc- esses. Post-abdomen with 5-6 anal spines. Claws smooth or den- ticulate. Antennules rather slender; lateral sense-hair somewhat distal to middle. Length of 9, ,5 mm.; d (South American), mm. Pools; Louisiana, Texas. The form with horn on vertex also is found in South America, mingled with typical C. rigaudi. Probably both forms should be in- cluded in C. cornuta Sars. Fig. 1078. Ceriodaphnia rigaudi. Si (50) Head without horn 52 52 (53) Claws Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ward, Henry Baldwin, 1865-1945; Whipple, George Chandler, 1866-1924. joint author. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
