I50 



the upper surface implanted a little before the middle, proportion between the length of the 

 telson and the distance of that pair from the posterior margin 1,7; proportion between the 

 distances of both pairs from the posterior margin 1,8. 



Both in the male and in the female the legs of the first pair are unequal. In the 

 male the left is the larger, the merus reaching as far forward as the carpocerite : this leg much 

 resembles that of the male oi Ath. diniorphus (H. Coutiere, Les "Alpheidae", 1899, Fig. 205). 

 Ischium 2,5-times as long as wide at the distal extremity, the straight upper margin supports 

 at the distal extremity a movable spine, the length of which is one-fourth that of the member, 

 another, half as long, just behind the middle and a third of the same length at the proximal 

 extremity. The merus, vaginiform along its whole length, is 2,3-times as long as the preceding 

 member, just 3-times as long as wide and closely resembles that of Ath. dimorphtis Ortm. 

 The short, conical carpus is about half as long as the ischium. The chela, one-third longer 

 than the merus, resembles that of Ortmann's species, but one observes a small tooth on the 

 lower margin near the carpal articulation; the chela is nearly 5-times as long as high. The 

 fingers that measure almost one-fourth the length of the chela, shut nearly together, while 

 their tips meet one another; the immobile finger carries one or two teeth. The dactylus which 

 is strongly curved, appears as thick at its base as the other finger. 



The other leg', in the male, much resembles the described one, but is smaller. Ischium 

 one-third shorter than that of the large cheliped, also 2,5-times as long as wide at the distal 

 extremity, but without movable spinules on the upper margin. Merus a little more than 3-times 

 as long as wide, shorter than that of the large cheliped, the proportion being as 3:5; its 

 shape is, however, the same. The carpus, exactly as long as in the larger leg, measures one- 

 third the length of the merus, but the chela which is 1,4 mm. long, appears half as long as 

 that of the larger cheliped, but only a little longer than the merus (1,29 mm.). The fingers 

 that shut together and the cutting-edges of which are entire, unarmed, measure almost one- 

 third the length of the chela, the proportion being 3,3; the chela is 4-times as long as high. 



In the female the right leg is the larger : it apparently agrees with the description and 

 the figure c of the cited paper. The ischium, 0,84 mm. long, is 3, 4-times as long as broad 

 distally, showing a more slender form than that of the larger cheliped of the male; but the 

 three spinules of the latter are implanted in the same manner. The merus that measures 

 1,26 mm., appears just one and a half as long as the ischium and 3,6-times as long as 

 wide; it appears more distinctly truncate at the distal e.xtremity and it narrows proximally less 

 considerably than in Fig. c of Coutiere's paper, the greatest width being in proportion to the 

 width at the proximal extremity as 25 : 14. Carpus exactly half as long as the merus and 

 twice as long as thick; it is one-fourth shorter than the ischium, the proportion being as 3 : 4. 

 Chela 1,54 mm. long, a little longer than the merus, the proportion being as 11:9; 

 palm a little shorter than the merus, the proportion being as 8:9, fingers a little less than 

 one-third the length of the chela, the length of the latter being in proportion to that of the 

 fingers as 11:3. The fingers that are tapering and shut together, are just as long as the 

 palm is high. 



The smaller leg has a quite different form and appears more slender. Ischium 



