's RIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. 107 



as wide ; dactylus simple, measuring one-third of the propodus and 6-times 

 as long as broad at its base. 



Ova small, 0,5 mm. long. 



Length 9,66 mm. from tip of rostrum to tip of telson (carapace 

 3,7 mm. long, abdomen 5,96 mm.), 



Synalpheus Sluiteri n. sp. 



1 full-grown egg-bearing female and 1 younger specimen, collected by 

 Prof. C. Ph. Sluiter in the Bay of Batavia. 



A new species of the Neomeris-grouip, closely related to Syn. para- 

 neomeris Cout. and its varieties. 



Rostrum rather slender, 2 1 / 2 -times as long as broad at base, as long 

 as basal antennular article, subacute ; lateral teeth triangular, one-fourth 

 shorter, with the acute tips slightly turned inward. Antennular peduncle 

 stout, only three times as long as wide, 2nd article just as long as wide, 

 2nd and 3rd together almost one and a half as long as the visible part 

 of 1 st . Upper angle of basicerite subacute, a little prominent, though not 

 spiniform. Carpocerite 3,85-times as long as wide, projecting beyond the 

 antennular peduncle by the whole length of 3rd article ; terminal spine 

 of scaphocerite a little shorter than the carpocerite, the lamella nearly 

 as long as the peduncle of the upper antennae. 



Telson as in Syn. paraneomeris, but the dorso-lateral spinules are 

 implanted nearer to the lateral margins. 



Upper border of the merus of the larger cheliped, (the smaller is 

 wanting), terminating distally in a small acute tooth, chela like in Syn. 

 paraneomeris. First segment of the carpus of 2nd pair a little longer than 

 the sum of the four following, 2nd and 3rd segment equal, 4*h a little 

 shorter than 3rd, chela as long as the sum of the four last joints of 

 the carpus. Merus of 3rd legs unarmed, 3,8 6-times as long as wide, pro- 

 podus 6-times as long as wide, with 4 spinules, long 0,15 — 0,17 mm., 

 on the lower margin besides the two at the distal extremity; relative 

 measurements: merus 2,24, carpus 1, propodus 1,95, dactylus (measured 

 to the tip of the ventral hook) 0,42 ; dactylus of a rather stout shape, 

 the width at the base being two-fifths the length, dorsal hook a little 

 longer than ventral, its thickness at the base two-thirds that of the 

 ventral hook. 



Ova few in number, large, 1,3 — 1,35 mm. long. 



Length 13 mm. 



(29— III— 1920) 



