346 The Philippine Journal of Science 1914 



posterior to them. On the lower border are 3 teeth, the distal 

 one of which lies some distance back of the tip. The peduncle 

 of the first antenna reaches almost to the tip of the rostrum. 

 One-third of the carpus of the fully extended first pair of legs 

 extends beyond the antennal scale. 



The left cheliped, which is a little longer than the right (not 

 true of all specimens), measures 266.5 millimeters, being a little 

 less than twice as long as the body. The immobile finger extends 

 farther forward than the mobile finger, and is not curved in- 

 ward so sharply. The fingers are a little more than one-half 

 as long as the palm (1 : 1.81), and in this specimen they gape; 

 that is, when their tips meet, there is an open space between 

 the fingers. Of the 2 teeth situated near the proximal end of 

 the mobile finger, the more distal one, which is subacute and 

 flattened laterally, is 2 millimeters high and 2 millimeters wide 

 at the base. The more proximal one is smaller, less acute, and 

 is flattened laterally. It measures 1.5 millimeters in height and 

 1 millimeter at the base. The cutting edge of the mobile finger 

 is seen with difficulty, being simply a very slightly raised ridge. 

 On each side of it is a row of 12 plainly visible tubercles, which 

 do not extend to the tip. There is no thick coating of hair as 

 in Palaemon nipponensis. On the immobile finger, which is also 

 without the thick coating of hair, is a large subacute tooth, which 

 is situated a little posterior to the distal tooth of the mobile 

 finger. It is conical in shape, measuring 2.5 millimeters in 

 height and 2 millimeters in width at the base. Back of this 

 tooth may be seen a series of 4 closely set teeth. The most 

 anterior of the 4, which is the largest, is on a level with the more 

 proximal tooth of the mobile finger. The second, third, and 

 fourth decrease gradually in size, and the last 2 are incompletely 

 separated. A series of 8 or 9 tubercles, similar to those on the 

 mobile finger, is situated along the inner side of the very in- 

 conspicuous cutting edge. The palm, which is almost cylindrical 

 in cross section, is flattened slightly laterally. It is of about the 

 same size throughout its extent, and is shorter than the carpus. 

 The cylindrical carpus, which reaches its greatest diameter (9 

 millimeters) some little distance back of the distal end, is much 

 shorter than the chela, while the slightly curved merus, which 

 is almost cylindrical near its distal end and decidedly flattened 

 near its proximal end, is much shorter than the carpus, showing 

 a ratio of 1:1.5. The much flattened ischium has its dorsal 

 and ventral surfaces divided into 2 regions by a longitudinal 

 groove. The lengths, in millimeters, of the parts of the cheliped 



