196 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



TISBE FURCATA (Baird) 



FiGXJKES 130, lola 



Canthocamptus furcatus Baird, The natural history of the British Entomo- 



straca, p. 210, pis. 25, 30, 1S50. 

 Idyaea furcata Sars, Crustacea of Norway, vol. 5, p. 88, pis. 51, 52, fig. 1, 1905. 



Occwi'vence. — Found in surface tows in Cuttyhunk Harbor; Pen- 

 zance Pond, Woods Hole ; Waquoit Bay, Falmouth ; Sengekontacket 

 and Nashaquitsa Ponds, Marthas Vineyard. 



Distiihution. — Atlantic Ocean, British Isles (Baird) ; Arctic 

 Ocean, Kattegat, French coast (Canu) ; Mediterranean, Red Sea 

 (Thompson and Scott) ; New Zealand (Thomson, Brady) ; Chatham 

 Islands, Norwegian coast (Boeck, Sars) ; Franz Josef Land (T. 

 Scott) : North Sea (Timm) ; Madeira (Fischer) ; Greenland (Buch- 

 holz) ; Gulf of Genoa (Brian) ; Adriatic (Car, Graeffe, Pesta) ; 

 Nova Zembla (Brady) ; Kiel Bay (Mobius, 

 Giesbrecht) ; Alaska, Passamaquoddy Bay 

 (Willey) ; Chesapeake Bay, Halifax, Nova 

 Scotia (Wilson) ; Narragansett Bay (Wil- 

 liams) ; Woods Hole (Sharpe, Fish). 



Color. — Body transparent, with faint trans- 

 verse bands of violet, the ovary and ovarian 

 tubes blue, appearing dark bluish black by 

 Figure 130.— ris6e fur- transmitted light, and showing distinctly 

 cafa; a, Male, fifth through the integument: the long setae on the 



leg ; h, female, fifth *= -, -i ^ ■ • T 



leg. (From R. w. antennae and caudal rami violet; eye dark 

 Sharpe, Proc. u. s. crimson (Rathbun). 



Nat. MUS., vol. 38, p. ^ , t. r , n- <• i n -1,1 



417) t emale. — Metasome elliptical, the width more 



than half the length; urosome half as long as 

 the metasome and tapered posteriorly; caudal rami one-half wider 

 than long, the second inner apical seta twice the length of the uro- 

 some. First antennae scarcely reaching the second metasome seg- 

 ment, their terminal portion 4-segmented ; third and fourth segments 

 of their basal portion each shorter than the second segment; distal 

 segment of fifth legs four times as long as wide; outer process of 

 basal segment long and slender. Total length, 0.8-1.2 mm. 



Mode. — Considerably smaller than the female, the urosome not so 

 sharply separated from the metasome; genital segment not divided; 

 first antennae geniculate, the terminal portion made up of two seg- 

 ments; fifth legs smaller, the distal segment little more than twice 

 as long as wide, its middle apical seta transformed into a stout den- 

 ticulated spine. Total length, 0.5-0.8 mm. 



Rei7i(iTks.—'Y\ns> is one of the most widely distributed harpactids 

 and is often found in large numbers close to the shore, among algae. 



