282 



but the merus is a little more slender (Confer the Table). The propodus of the adult 

 male bears ten spinules that are 0,16 — 0,17 mm. long, that of the young specimen from Banda 

 six, long 0,044 — 0,075 mm - Measured from the base of the anterior margin to the tip of the 

 ventral hook, the dactylus measures in the adult male a little more than one-seventh, in the 

 young specimen one-fifth of the length of the propodus. The dactylus is half as broad at its 

 base as it is long; the ventral hook is twice as long as wide at its base and its anterior margin is 

 almost perpendicular to the posterior margin of the dactylus ; dorsal hook one and a half as long 

 as the other and one and a half as wide at its base, measured from the suture to the anterior 

 margin. The two hooks hardly diverge and the notch between them is concave at the base. 



Table A. 



Proportion between length of telson and width of posterior margin 



Proportion between the width at the base and that of posterior margin 



Proportion between the length of telson and the distance of the anterior pair from 



the posterior margin 



Proportion between the distances of both pairs from the posterior margin 



Table B. 



Merus 



Relative dimensions of ( Carpus 



Propodus 



Proportion between the length of the merus and that of the propodus. 

 Proportion between the length and the width of the merus . 

 Proportion between the length and the width of the propodus . 



of third lees 



N° 1 adult male from Stat. 33; N° 2 young specimen from Banda. 



The adult male from Stat. 33 is 15 mm. long, the ova-bearing female 14 mm.; ova few 

 in number, 0,75 mm. long. 



734. Synalpheus triacanthns de Man. 



J. G. DE Man, in: Tijdschr. d. Ned. Dierk. Vereen. (2) Dl. XI, 1910, p. 301. 



Stat. 289. January 20. 9°o'.3S., 126° 24'. 5 E. Timor Sea. 112 m. Mud, sand and shells. 1 male, 

 found in a specimen of Solenocaulon Gray. 



A new species of the Biïtnguicïdatïis group, distinguished, like Syn. trispinosiis de Man, 

 by the posterior margin of the 6 th abdominal somite being armed w i t h three s p i n e s. 



Rostrum long, slender, acuminate, with the tip curved upward and reaching to the 

 2 ud third part of median antennular article; the free part of the rostrum, vvhich is obtuse above, 

 is a little more than 4-times as long as wide at its base. Lateral spines slender and pointed, 

 slightly directed ontward and upward, measuring a little more than one-third the length of the 

 free part of the rostrum, and extending almost to the middle of the visible part of first anten- 

 nular article. Notches between the lateral spines and the rostrum rather wide, the notches as 

 wide anteriorly as they are long. Antennular peduncle 4,1-times as long as wide at the apex 



