. Bulletin - United States National Museum. Figure 13.—Stygonedes tenuis potomacus, new subspecies. Male ( mm), Glencarlyn,Va.: a, lower lip; b,c, right and left mandibles; d, maxilla 1; e, lateral sternal gill;/,maxilla 2; g, maxilliped; h,i, uropods 1,2. Male ( mm), Burleith Woods, Wash-ington, :;, telson; k, uropod 3; /, terminal flagellar segments of antenna 2. 64 NATIONAL AIUSEUM BULLETIN 2 59 although this graph is based on data gathered from specimens assignedto S. t. potomacus, it can be readily applied to either subspecies. Assize increases, length of antenna 2 appr
. Bulletin - United States National Museum. Figure 13.—Stygonedes tenuis potomacus, new subspecies. Male ( mm), Glencarlyn,Va.: a, lower lip; b,c, right and left mandibles; d, maxilla 1; e, lateral sternal gill;/,maxilla 2; g, maxilliped; h,i, uropods 1,2. Male ( mm), Burleith Woods, Wash-ington, :;, telson; k, uropod 3; /, terminal flagellar segments of antenna 2. 64 NATIONAL AIUSEUM BULLETIN 2 59 although this graph is based on data gathered from specimens assignedto S. t. potomacus, it can be readily applied to either subspecies. Assize increases, length of antenna 2 approaches the length of antenna 1,and in males between and mm both antennae become aboutequal in length. Males over mm in length, however, typically 2nd Antenna Xh- o•z hi 111 h- :z< 3 St Antenna X / X. 5 6 7 8 9 10 11 STANDARD LENGTH, MM 12 13 Figure 14.—Relation of antenna! length to standard length (body length excluding appen-dages) in Stygonedes tenuis potomacus from seeps in Burleith Woods, Washington, [Antenna 1 (solid circles), antenna 2 (xs). Regression line calculated by the leastsquares method.] SUBTERRANEAN AMPHIPOD STYGONECTES 65 have tlie second antennae longer than the first antennae, and in verylarge males the former may appreciably exceed the latter in length asshown. In the largest males examined ( mm) the secondantennae were 27 percent longer than the first antennae. But onlytwo specimens were found which had attained this length; the majorityof males were much smaller and the largest otherwise was mm. Type locality.—Bog in Burleith Woods, Glover Archbold Park-way, Washmgton, A small stream flowing through BurleithWoods is fed by a mnnber of small subterranean seeps which eitherflow directly into this creek or form swamps and bogs along
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