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DEPARTMENT OF THE NAVAL SERVICE 



the male of U. minor differs from that of U. major in the absence of the forceps mecha- 

 nism described by Esterly on the left foot and in some other respects. The chief 

 differences are displayed in table Q, supplemented by text-fig. 7 and 8. The postero- 

 lateral angles of the forebody are rounded; rostrum strongly deflexed; anterior 

 antennas exceed length of forebody. 



%.^ 



Fig. 8. — Undenrha'ta minor cf 

 Right fifth foot from behind. 

 i?e = outer branch. 



Fig. 7.— .Same. Left fifth foot. 



Table Q. — Comparison of fifth feet (p5) of U ndeuchaeta major and minor 6. 



Features. 



Length 



Right p5 



Outer branch (Re) 



Inner branch (Ri) 



Left p5 



Re 



Re. 



Undeuchaeta major cj' 

 (after Esterly. ) 



6 ■ 5mm 



Biramous 



Terminal joint produced into a long stylet. 



Siniule . 



Biramous 



Terminal joint ending in a short style 

 which carries a pencil of long hairs near 

 its centre. Second joint bearing a toothed 

 process " which flares distally " ; " at the 

 base of this and on the second joint is 

 aniculated a process, which together 

 with the terminal joint of the ramus and 

 the toothed process forms a forceps. " 



Vestigial 



Undeuchaeta ■miiiord' 

 ("Acadia " material.) 



3 5 mm. 



Biramous (fig. 8) 



Terminal joint with spoon-shaped 

 e.vtremity. 



.Simple. 



Biramous (fig 7). 



Terminal joint ending in a stylet 

 with a pencil of long hairs to- 

 gether with somedenticulations 

 near its centre, and a stout thorn 

 at its base. Second and third 

 joints incompletely separated. 



Vestigial 



