150 



BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



MALES 



1. Apical spines of left fifth leg obtuse; hand of chela on right 



leg with a single laminate process between bases of thumb 



and finger lobiancoi (p. 154) 



Apical spines of left leg acuminate; hand of chela with 

 2 processes between the bases of thumb and finger 2 



2. End segment of left fifth leg with 2 equal apical spines, 2 on 



outer margin, and rows of long hairs on posterior surface- securifer (p. 151) 

 End segment of left fifth leg with 1 large apical spine, 2 much 



smaller ones at its base and no rows of hairs 3 



3. Second basipod of right leg as long as hand of chela ; finger just 



meeting tip of thumb meadii (p. 153) 



Second basipod of right leg much shorter than hand of chela ; 

 finger extending considerably beyond tip of thumb pennata (p. 150) 



PONTELLA PENNATA Wilson 



Figure 101 



Pontella pennata Wilson, Proc. U. S. Nat. Mus., 

 vol. 80, art. 15, p. 27, pi. 1, 1932. 



Occurrence. — One female in surface tow, 

 ' Vineyard Sound, August, 1881 ; 10 males and 



females in Great Harbor, "Woods Hole, by 

 V. N. Edwards, September, 1887. 



Distribution. — Chesapeake Bay (Wilson) ; 

 Woods Hole Harbor (Fish). 



Color. — Body fairly transparent and deep 

 blue with a greenish tinge, the color darker 

 at the joints of the appendages, especially 

 those of the fifth legs in the male, and in 

 the grooves between the body segments. The 

 swollen middle section of the grasping an- 

 b tennae of the male also shows the same dark- 



FiGDRE 101. — Pontella pen- bluC Color. 



TegTUaie'^fi'fi'egs""' Femalc-Bodij stout and cylindrical; left 

 posterior lobe of the fifth segment larger 

 than the right; dorsal surface of the genital segment with a chitin 

 outgrowth on either side of the mid line, which passes forward onto 

 the dorsal surface of the thorax, and from the right one a ragged 

 streamer as Jong as the entire body extends backward ; urosome 2-seg- 

 mented and very short ; caudal rami symmetrical ; fifth legs much 

 reduced in size, the endopod four-fifths as long as the exopod and 

 tipped with two unequal spines. Total length, 3-3.25 mm. 



Male. — Lobe at right posterior corner of fifth segment larger than 

 the left and bifurcate at its tip ; urosome 4-segmented, symmetrical ; 

 no outgrowths on dorsal surface of genital segment; fifth legs large, 

 reaching nearly to the tips of the caudal setae; left one tipped with 



