. Bulletin of the British Museum (Natural History), Geology. MIDDLE JURASSIC OSTRACODA FROM NORTH LINCOLNSHIRE 181 ment of a kidney-shaped scar. Species of Progonocythere are liable to possess either a rounded or a kidney-shaped antennal scar. In this type the antennal scar is usually situated anterodorsally, but may vary within a species and sometimes ap- proach the anteromedian position. #' mi â n Figs. 5-7. Type A muscle scar pattern. Fig. 5, Progonocythere sp. nov. X 250. Figs. 6 (X300), 7 (X200), Progonocythere bajociana sp. nov. Type B In a large number of ostracod genera the antennal sc
. Bulletin of the British Museum (Natural History), Geology. MIDDLE JURASSIC OSTRACODA FROM NORTH LINCOLNSHIRE 181 ment of a kidney-shaped scar. Species of Progonocythere are liable to possess either a rounded or a kidney-shaped antennal scar. In this type the antennal scar is usually situated anterodorsally, but may vary within a species and sometimes ap- proach the anteromedian position. #' mi â n Figs. 5-7. Type A muscle scar pattern. Fig. 5, Progonocythere sp. nov. X 250. Figs. 6 (X300), 7 (X200), Progonocythere bajociana sp. nov. Type B In a large number of ostracod genera the antennal scar is distinctly cresentic in outline, generally with the opening of the crescent directed anteriorly (Text-fig. 10). Possibly related is the condition where the antennal scar is directed obliquely antero- dorsally, a condition somewhat akin to type D described below. The crescentic antennal scar is not considered to be related to the kidney-shaped scar of the previous type (A). A mandibular support spot (" mandibular stutzfleck " of Triebel) is commonly associated with this muscle scar type, and further research may prove this association to be significant. 2r. :;ri01v a**"*88 â m. "*sg*. " "A , - ' -,? ' -'-''â ' i 8 10 Figs. 8-10. Type B muscle scar pattern. Figs. 8 (X200), 9 (X320), Dolocythere maculosa sp. nov. Fig. 10, gen. nov. x 240 Type C The most common position for the antennal scar, relative to the adductor scars, appears to be anterodorsal. Amongst several related Bajocian ostracod genera the. 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 British Museum (Natural History). London : BM(NH)
Size: 1742px × 1435px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbritishmuseumnaturalhistory, bookcentury1900, bookcoll
