284 



Relative proportions of third legs : merus 2,4; carpus i; propodus 2, the merus 1,21-times 

 as long as the propodus. Though these proportions are nearly the same as in Syn. trispinosus, 

 these joints show a more slender shape and the merus is quite unarmed. The merus 

 indeed is 4,5-times as long as wide, the propodus 6,6-times and the latter bears ten spinules 

 0,15 — 0,17 mm. long. Measured to the tip of the ventral hook, the length of the dactylus 

 proves to be one-eighth that of the propodus and twice the width near the articulation. The 

 rather small, ventral hook appears about twice as long as broad at its base and its anterior 

 margin is directed o b 1 i q u e 1 y with regard to the posterior margin of the dactylus ; the m u c h 

 longer and stronger, dorsal hook is twice as long and twice as broad at its base, 

 measured from the suture to the anterior margin of the dactylus, than the ventral hook ; the 

 two hooks very slightly diverge and the notch between both is concave internally. Merus of 

 4 th pair also unarmed. 



The appendages of the five pleopods are y e 1 1 o w i s h green coloured. 



Length 16 mm. 



■J" 35. Synalpheus quadridens de Man. 



J. G. de Man, in: Tijdschr. d. Ned. Dierk. Vereen. (2) Dl. XI, 1910, p. 299. 



Stat. 282. January 15/17. 8°25'.2S., i27°i8'.4E. Anchorage between Nusa Besi and the N.E.- 

 point of Timor. 27 — 54 m. Sand, coral and Lithothamnion. 1 ova-bearing female. 



Like in Syn. quadrispinosus de Man, the posterior margin of the 6 th abdominal somite 

 is armed with four teeth, but Syn. quadridens, which also belongs to the Biunguiculatus 

 group, differs by the stouter shape of the legs and some other differences. Unfortunately 

 the large cheliped and the second legs are missing. 



Frontal and antennal region much resembling those of Syn. pachymeris (H. Coutière, 

 Alpheidae Mald. and Laccad. Archip. 1905, PI. LXXI, Fig. 9). Rostrum slender, about 4-times 

 longer than wide in the middle, with the tip rather obtuse and almost reaching to the middle 

 of the visible part of first antennular article ; lateral frontal teeth a little longer than the 

 rostrum, reaching just to the middle of the visible part of first antennular article, much wider 

 than the rostrum and much wider at their base than they are long ; notches between the rostrum 

 and the lateral teeth, that are also rather obtuse at the tips, narrow, the distance between the 

 tip of the rostrum and that of a lateral tooth being shorter than the latter are long. The outer 

 margin of the lateral teeth is regularly curved, convex. 



Antennular peduncle stouter than that of Syn. quadrispinosus, 4-times longer than 

 wide at the apex of median article; the proportion between the length of the three articles just 

 as in Syn. quadrispinosus. Stylocerite shorter than in this species, reaching to the 2 nd third 

 part of median antennular article. 



Carpocerite 5-times longer than wide in the middle, extending beyond the antennular 

 peduncle by half the length of the 3 rd article or a little more ; terminal spine of the scaphocerite 

 as long as the antennular peduncle, the tip slightly directed outward and projecting by one- 

 third its length beyond the narrow scale that reaches to the apex of median antennular article. 



iS 2 



