. Fresh-water biology. Freshwater biology. THE WATER-MITES (HYDRACARINA) 863 18 (7) Distal extremity of pal. seg. 4 slightly or not at all produced be- yond the insertion of seg. 5, but the latter free, tapering, the tip bearing smaU claws or teeth, or ending in a sharp point. Family Hygrobatidae . 19 19 (22) Pal. seg. s sharply pointed, claw-like, opposable to the projecting distal flexor margin of seg. 4, forming a sort of pincer. Body entirely covered by a porous sheet of chitin, divided by a suture into a smaller dorsal portion and a larger ventral. Legs with swimming hairs. Subfamily Arrh
. Fresh-water biology. Freshwater biology. THE WATER-MITES (HYDRACARINA) 863 18 (7) Distal extremity of pal. seg. 4 slightly or not at all produced be- yond the insertion of seg. 5, but the latter free, tapering, the tip bearing smaU claws or teeth, or ending in a sharp point. Family Hygrobatidae . 19 19 (22) Pal. seg. s sharply pointed, claw-like, opposable to the projecting distal flexor margin of seg. 4, forming a sort of pincer. Body entirely covered by a porous sheet of chitin, divided by a suture into a smaller dorsal portion and a larger ventral. Legs with swimming hairs. Subfamily Arrhenurinae. 20 20 (21) Genital area lying between epp. IV, the cleft flanked by large valves each bearing 3 or 4 acetabula. Krendowskija Piersig 1895. A dark brown mite of medium size, broadly oval in form; witli the capitulum movable and protrusible, and the camerostom developed into a long rostrum, sabre-like and curved upward. One American species, K. ovaia Wolcott, occur- ring rarely in Wisconsin and Michigan. Other species are described from Venezuela and southern Russia. Each is a little over i mm. in length. Fig. 1330. Krendowskija ovata Wolcott. Epimeral area and genital area, female. X 75. Inner side, left palpus, female. X 250. Side view of female, showing proboscis. X 60. (After Wolcott.) 21 (20) Genital area lying posterior to epp. IV, the cleft flanked by two plates forming together an elliptical or circular area, beyond which are laterally extended, wing-like plates with numer- ous acetabula Arrkenurus Duges 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. ]
Size: 1507px × 1658px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
