15 



alono- the upper margin of the joints are the following. Of the i st pair (Fig. 8 c) the merus is 1,08 mm. 

 long, wide in the middle 0,23 mm., proportion 4,7; carpus 1,25 mm. long, 0,235 mm - w 'de 

 at the distal extremity, proportion 5,3; chela 0,8 mm. long (palm 0,32 mm., fingers 0,48 mm.). 

 Of the 2 nd pair (Fig. 8d) the merus is 1,48 mm. long, 0,2 mm. wide in the middle, proportion 7,4; 

 i st segment of the carpus 0,92 mm. long, 0,16 mm. thick at the distal extremity, 6-times as 

 long as thick distally ; 2 nd segment 0,3 mm. long, 3 rd 0,24 mm., 4 th 0,44 mm., entiru length 

 of the carpus 1,9 mm., i,2S-times as long as the merus ; chela 1 mm. long (palm 0,44 mm., 

 fingers 0,56 mm.). Different from the type the i st segment is a little shorter than the three 

 following taken together and has a somewhat less slender shape, like also the merus. In another 

 female with eggs the merus proved to be 1,36 mm. long and 0,18 mm. broad, proportion 7,5 ; 

 carpus 1,87 mm. long, 1,37-times as long as the merus, the segments being from the i st to 

 the last respectively 1 mm., 0,25 mm., 0,22 mm. and 0,4 mm. long, the i st segment o, 14 mm. 

 thick at the distal extremity; chela 0,78 mm. long (palm 0,36 mm., fingers 0,42 mm.). In this 

 female the i st segment is a trifle longer than the three following taken together and also, like 

 in the type, appears more slender than in the first. 



Of the 3 rd pair the merus (Fig. 8*) is 0,96 mm. long, its greatest width, anteriorly there where 

 the spine is implanted, 0,28 mm., proportion 3,4; carpus long 0,66 mm. and 0,22 mm. broad, 

 proportion 3; propodus long 0,44 mm., broad 0,2 mm. proximally, 2,2-times as long as broad ; 

 dactylus 0,34 mm. long, 0,04 mm. broad, 8-times as long as broad. The relative dimensions 

 of merus, carpus and propodus are therefore : merus 1,45; carpus i; propodus 0,66. 



Of the 4 th pair (Fig. 8/) the ischium is 1,1 mm. long; the merus 1,4 mm. long, 0,22 mm. wide, 

 proportion 6,4; carpus 0,92 mm. long, 0,18 mm. broad, proportion 5,1; propodus 0,82 mm. 

 long, 0,14 mm. broad in the middle, proportion 5,7; dactylus 0,26 mm. long, 0,035 mm. broad, 

 proportion 7,4. The relative measurements are: merus 1,52; carpus i; propodus 0,9. 



Of the 5* pair, finally, the slender ischium (Fig. 8^) is 1,8 mm. long, in the middle 0,08 mm. 

 thick, proportion 22, while it is 0,12 mm. thick at the distal extremity; merus 0,9 mm. long 

 and 0,12 mm. broad in the middle, proportion 7,5, the merus is, however, 0,13 mm. thick 

 at the distal extremity; carpus long 0,4 mm., 0,16 mm. thick at the distal extremity, pro- 

 portion 2,5; propodus 0,62 mm. long, 0,18 mm. broad in the middle, proportion 3,4; dactylus 

 0,46 mm. long, 0,073 mm - broad at base, proportion 6,3. The relative measurements are: 

 merus 2,25; carpus i; propodus 1,55. Ischium twice as long as merus. 



Eggs globular, diameter 0,18 — 0,2 mm. 



O. striaticauda Kemp appears closely related, but apparently differs by the larger (7 to 9) 

 number of forwardly directed spines on the carapace, by the absence of the posterior ridge on 

 the ventral surface of the telson and apparently by some slight differences in the measurements 

 of the peraeopods. The scaphocerite has another form and there are probably still other differences. 

 According to Mr. Kemp's description the telson should not possess a feeble lateral prominence, 

 1. c. p. 2SS, but in the text-figures / and g such a prominence is visible, appearing in Fig. / 

 as much developed as in O. Sibogae. 



General distribution: Sulu Sea (de Man). A probable variety occurs east of Dangar 

 Besar, Saleh-bay. 



