4°5 



The following legs are also very slender, their meri unarmed ; the meri of the 3 rd legs 

 are 8,8-times as long as broad, smooth and glabrous. Ischium of 3 rd and 4 th legs with 

 movable spine. 



Etrsfs small and numerous. 



General dist.ribution: Bay of Bengal (Alcock, Anderson); Andaman Sea (Alcock, 

 Anderson). 



V. Ediuardsii group. 

 748. Alpheus bis-incisus de Haan. 



Alpheus bis-incisus W. de Haan, Fauna Japonica, Crustacea, 1849, p. 179, Tab. XLV, fig. 3. 

 Alpheus bis-incisus H. Coutière, Alpheidae Mald. and Laccad. Archip. 1905, p. 910, 911. 



May 16. 1909. North-coast of Sumatra, to the east of Segli. 40 — 70 fathoms. 1 male and 

 1 ova-bearing female collected by Mr. VAN NOUHUIJS. 



Unfortunately the female has lost both legs of the i st pair, while the male bears still 

 only the small cheliped. 



Rostrum of the female (in the male the tip is broken) acute, reaching almost to the 

 end of i st antennular article, the flattenecl triangle just twice as long, measured in the 

 middle line, as widë at its base and extending a little behind the corneae, so that the distance 

 between the outer angles of the base and the corneae appears half as long as the latter. The 

 frontal margin shows a rounded prominence near the rostrum, from which it is separated by 

 an emargination ; both this prominence and this emargination are more conspicuous than in 

 the variety Malensis (H. Coutière, 1. c. Fig. 48). Antennal region as in this variety, but the 

 2 nd antennular article is one-third longer than the visible part of the i st and the blacle of the 

 scaphocerite appears in the male a little shorter than the antennular peduncle, in the female 

 nearly as long. 



In the small cheliped of the male the apex of the upper margin of the merus is obtuse 

 and unarmed, while a few setae are inserted on it; the two other margins are also quite 

 unarmed. Chela hardly more than 4-times as long as high, palm a little shorter than the fingers, 

 the proportion being as 4:5. Lower border of the chela rounded, entire, upper border notched 

 a little behind the articulation of the fingers, the notch passing on the outer side into a 

 quadrangular depression or groove, while the inner side of the palm is smooth, entire and 

 convex, in accordance with de Haax's description ; the fingers shut close together, the dactylus 

 is smooth at the inner side, but one observes on the outer side a row of hairs that runs 

 obliquely from the base upward to the middle of the upper border. The upper border of the 

 dactylus is somewhat flattened at the base and hairy, some rather long setae are inserted also 

 on the immobile finger and on the upper border of the palm. 



Second carpal segment of 2 nd legs shorter than the i st , the proportion being 1,6 — 1,7. 



Measurements of 3 rd legs in the female: merus 1,85; carpus i; propodus 1,44. Merus 

 6-times as long as wide, propodus 7,5-times; the propodus bears 7 spinules, long o, 37 — 0,52 mm., 



273 



S1BOGA-EXPEDITIE XXXIX a'. 5 2 



