31 



in: J. G. DE Man, Siboga Exp., Monogr. XXXIX fl\ Part II, Family Alpheidae, 191 1 (text), 

 p. 273, 1915 (plates) PI. XI, fig. 51 — 5 1 </, but which no doubt is a different form. The 

 differences presented by the female from Stat. 144 are, however, slight and trifling, this spe- 

 cimen may perhaps prove to belong either to Syn. pachymeris Cout. or to the Syn. biungui- 

 citlat2is of the "Siboga Alpheidae" and I therefore hesitate to describe it as new, because the 

 variability of some characters is still unknown in these species. 



Rostrum (Fig. 15) rather obtuse, 3-times as long as wide in the middle, reaching not yet 

 to the middle of the visible part of basal antennular article ; lateral spines as in Syn. biungtii- 

 £ulatus (Stimps.) Cout. (H. CouTiiiRE, 1. c. fig. 8), triangular, rather obtuse, only a trifle shorter 

 than the rostrum, less broad than in Syn. pachymeris (H. Coutiere 1. c. fig. 9). * 



Antennular peduncle 4Y3-tiiTies as long as the 2'"' article is wide distally; visible part 

 of basal article one and a half as long as 2"<i, 2"<i one-third longer than wide distally, 3'^'^ 

 article as long as 2"'', not shorter. Upper spine of basicerite well developed, as long as 

 the rostrum, lower spine a little longer than the basicerite itself and than the stylocerite that 

 just reaches beyond the distal extremity of basal article. Carpocerite 5-times as long as broad, 

 projecting beyond the antennular peduncle by two-thirds of the 3'''^ article ; terminal spine of 

 scaphocerite a little shorter than the antennular peduncle, lamella reaching to the far end of 

 2°"^ article, outer margin of scaphocerite slightly concave. 



The telson (Fig. i5«) fully resembles that of the male from Stat. 282 (J. G. de Max, 1. c. 

 ^g- 5 0^ ''^ is 3-times as long as the posterior margin is wide and the proportion between the 

 width at the base and that of the posterior margin is 2,26; the dorso-lateral spinules are rather 

 large, those of the anterior pair are 0,18 mm. long, those of the posterior 0,2 mm.-, pro- 

 portion between the length of the telson and the distance of the anterior pair from the posterior 

 margin 1,46, proportion between the distances of both pairs from the posterior margin 1,55. 

 The postero-lateral angles are acute, though very short ; the posterior margin appears convex, 

 though not so much as in Coutiere's figure 8</: when the postero-lateral angles are united 

 by a transverse line, the length of this line, i. e. the width of the posterior margin, is in 

 proportion to the length, in the middle line, of the convex part posterior to this line, like 23:4, 

 in the figure Srt', however, like 23 : 6. 



Large cheliped on the left side. Merus twice as long as broad, with an acute tooth at 

 the distal extremity of the upper mai-gin. Relative dimensions of the large chela: fingers i, 

 total length 3,53, height 1,17. The larger chela is just 3-times as long as high in the plane 

 of the fingers, which are rather short, measuring little more than one-fourth the total length, 

 and the dactylus is strongly curved ; the slightly convex upper border of the palm ends distally, 

 at the supero-internal angle, in a rather small obtuse tooth, that is directed straight 

 forward. The large chela is 2,65-times as long as the smaller, of which the relative dimensions 

 are: fingers i, total length 2,66, height 0,82; this chela appears also about 3-times as long 

 as high and the fingers measure three-fifths of the palm. The merus of the small cheliped is 

 2,8 or 2,9-times as long as broad and the upper border is unarmed at the distal extremity. 



Merus of 2°"^ legs 4,7-times as long as wide in the middle. First carpal segment 3'/.5-times 

 as long as thick at the far end, the sum of the four following segments is 1,28-times as long 



