38; 



Balikpapan this chela is 16,5 mm. long, the palm is 5,25 mm. long and 4,5 mm. high at the 

 articulation of the fingers, so that it appears slightly longer than high. The fingers that leave 

 a hiatus between them when closed and that are excavate at the inner side, are thickly beset 

 with hairs on their prehensile edges and on the inner side; they are twice as long as the palm. 

 The dactylus, 2 mm. high at the outer side, appears, as in A. distijiguendus , nearly 5-times as 

 long as high and not 4-times as in the typical brevirostris ; the lower margin appears therefore 

 also less strongly undulate than in the latter species. The outer and the inner side of the 

 dactylus are finely granulate and the granulation extends on the base of the immobile finger, 

 but for the rest this finger and the dactylus are smooth. 



In both legs of the 2"^ pair of the male the merus is 7,7-times longer than wide; in 

 the female the merus is injured. Of the left leg of the male the carpal segments are ■^y,'] mm., 

 3,4 mm., 1,3 mm., 1,14 mm. and 1,5 mm. long, the chela 2,8 mm. long (palm 1,28 mm., fingers 

 1,52mm.); in the right leg these numbers are, for the carpus: 3,7mm., 3,5mm., 1,3mm., 

 1,14 mm. and 1,6 mm., for the chela 2,8 mm. (palm 1,2 mm., fingers 1,6 mm.). In the female 

 the carpal segments are 4,4 mm., 3,7 mm., 1,8 mm., 1,64 mm. and 2 mm. long, the chela 

 3,3 mm. (palm 1,5 mm., fingers 1,8 mm.). In both legs of the male the i^' segment is 5,6-times, 

 the 2°'! 5,6 to 5,8-times as long as thick at the distal extremity, in the female the i*' segment 

 5, 5-times, the 2"^^ almost 5-times. Differently from the typical species the 2°<i segment appears 

 a little shorter than the i^' and the carpus shows also a less slender form, for in the New 

 Holland species the 2"^ segment is described as being about 7-times as long as wide (J. G. 

 DE Man, 1. c. p. 156). The 4"^ segment appears constantly a litde shorter than the 3''' and the 

 3''' a little shorter than the 5"' ; the fingers are slightly longer than the palm. 



Merus of 3''^ legs in the male 4, 5-times longer than wide. 



Table of measurements in millimeters. 



Length of the telson 



Width at the base 



Width of the posterior margin 



Proportion between the lengtli of the telson and the width at the base 



Proportion between the length of the telson and the width of the posterior margin . 

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



spinules from the posterior margin 



Proportion between the distances of both pairs of spinules from the posterior margin . 



N° I and X" 2 Balikpapan; N" 3 type oi A. brevirostris (Oliv.) from the Paris Museum. 



N»3- 



6,8 



3.5 



1.94 



J 39. Alpheus barbatus Cout. 



Alpheus barbatus H. Coutiere, in: Bull. RIus. Paris, 1897, N" 6, p. 235 and in: Les "Alpheidae", 

 Morphologie externe et interne etc. Paris, 1899, p. 230, figs. 279, 280 and in: Alpheidae 

 Maid, and Laccad. Archip. 1905, p. go6. 



Stat. 34. i\Iarch 27. Anchorage off Labuan Pandan, Lombok. Coralreef i young specimen. 

 Stat. 142. August 5/7. Anchorage off Laiwui, coast of Obi Major. Reef, i young specimen. 



255 



