COPEPODS OF THE WOODS HOLE REGION 



197 



Living specimens can be told by their large size and peculiar color, 

 in preserved material the tufted cilia on the spines of the first exo- 

 pods will locate the genus and a comparison of the fifth legs will 

 determine the species. 



TISBE LONGICORNIS (T. and A. ScoU) 



Figure 131?> 



Idya longicornis T. and A. Scott, Ann. Mag. Nat. Hist., ser. 6, vol. 15, p. 461. 

 pi. 17, 1895.— Saks, Crustacea of Norway, vol. 5, p. 92, pi. 54, fig, 1, 1905. 



Occurrence. — Three females were obtained in a surface tow along 

 the edge of the eelgrass in Cuttyhunk Harbor, July, 1925. 



Distribution. — Scottish coast (T. and A. Scott) ; Norwegian coast 

 (Sars) ; Ceylon, Indian Ocean (Thompson and Scott) ; Adriatic 

 (Grandori, Pesta). 



Color. — Body transparent, with a slight tinge of blue; a band 

 of dark violet across the posterior portion of the cephalic segment, 

 and another across the an- 

 terior part of the abdomen : 

 the bases of the legs show 

 through the transparent 

 thorax as transverse dark 

 bands; eye dark red. 



Female. — Body slender, 

 the epimeral plates broader 

 than in furcata; urosome 

 narrow and only slightly 

 tapered posteriorly ; caudal 

 rami wider than long, the 

 second inner apical seta 

 fully three-fourths as long 

 as the entire bod3^ First 

 antennae reaching the third, 

 metasome segment, their third and fourth segments each longer 

 than the second segment, the four terminal segments combined 

 scarcely longer than the fourth segment. Distal segment of fifth 

 leg at least six times as long as wide, with three unequal apical setae 

 and two on the outer margin. Total length, 1.5-1.7 mm. 



Male. — Unknown. 



Remarks. — This species can be recognized by the length of the 

 first antennae, especially the fourth antennal segment, and by the 

 details of the fifth legs. It has never before been reported from 

 our American coasts. 



Figure 131. — a, Tisbe furcata, female, dorsal ; h, 

 T. longicornis, female, fifth leg ; c, T. loilsoni, fe- 

 male, fifth leg (typical) 



