398 The Philippine Journal of Science i9u 



One-half of the carpus of the first pair of legs extends beyond 

 the antennal scale, and the distal segment of the outer maxillipeds 

 extends beyond the peduncle of the second antenna. 



The chelipeds are decidedly unlike in form and unequal in 

 length, the larger being much longer than the body. One-third 

 of the merus of the larger and two-thirds of the carpus of the 

 smaller cheliped extend beyond the antennal scale. Measuring 

 in a straight line from the articulation of the mobile finger (large 

 cheliped) to the tip of the same, the length is 25.5 millimeters. 

 This finger is strongly curved inward, it is slightly compressed 

 near the tip, and it crosses the tip of the immobile finger when 

 the fingers are closed. Near the proximal end of the mobile 

 finger, along the cutting edge, are 5 low blunt teeth, followed 

 distally by a space at the end of which there is a rather large 

 subacute tooth. Beyond this, the cutting edge, which runs more 

 and more toward the outer surface of the finger as the tip is 

 approached, bears 14 low tubercles, which gradually decrease in 

 height toward the distal end of the finger. The immobile finger, 

 which is almost straight when seen in side view, curves inward 

 slightly and, although compressed laterally, is not concave on 

 its outer surface. It is one and one-half times as wide as the 

 mobile finger at the proximal end. There is a conspicuous 

 distally directed tooth on the cutting edge at the proximal end 

 of the immobile finger, and between this tooth and the articulation 

 of the mobile finger is a short low ridge, which possibly in older 

 specimens may be broken up into small confluent teeth. Along 

 the cutting edge, distal to the conspicuous tooth, 13 tubercles may 

 be seen, which gradually decrease in size as the tip of the finger 

 is approached. A few scattered hairs are present on both 

 fingers, and the elongated, anastamosing, longitudinal grooves 

 described by de Man as characteristic of Palaemon oenone can 

 be seen easily with a low-power lens. 



The palm, which is strongly compressed, measures 26 milli- 

 meters in length, 12 millimeters in width at its widest point, 

 and 7 millimeters in thickness in the same region. From these 

 figures it will be seen that the mobile finger (measured as de- 

 scribed above) is almost equal in length to the palm and that 

 the ratio of the thickness of the palm to the greatest width is 

 about 1:1.71. The palm decreases suddenly in width near its 

 proximal end where it is clothed, especially on its superior and 

 inferior borders, by a thick feltlike growth of hairs. On the 

 rest of the palm no hairs can be seen. 



The short, much inflated carpus, which is cylindrical in cross 

 section and much smaller in diameter than the width of the distal 



