ix, d, 4 Cowles: Palaemons of the Philippine Islands 379 



the fifth leg measures 10.5 millimeters in length, and has a 

 width of 0.5 millimeter at its middle point. 



Telson. — The telson of a large male has been described above. 

 In young specimens the telson tip is subacute, the externolateral 

 spines, extend posteriorly almost as far as the telson tip, and 

 the internolateral spines overreach the tip by more than two- 

 thirds of their length. 



Character of the surface. — The carapace and abdominal so- 

 mites of all females (Nos. 15, 16, 17), "male feminises" (Nos. 

 9, 11, 13), and young immature males (Nos. 1, 2, 3, 4, 5, 6) 

 are smooth to the touch, and show no spines under a lens. 

 Young mature males and old mature males (Nos. 7, 8, 10, 12, 

 14) have spines on the carapace, pleura of the abdomen, tergum 

 of the sixth somite, the uropods, and the telson. The surface 

 of the first pair of legs is smooth, except in the old males where 

 the ischium presents a few feeble spinules. No spines can be 

 seen on the chelipeds of the smallest male and female specimens 

 (Nos. 1 and 15). Very minute and feeble spinules, which can 

 only be seen under a rather high power lens, are present on the 

 palm, carpus, and merus of specimens Nos. 2 and 16. The 

 spines are more conspicuous in specimens Nos. 3 and 17. In 

 the medium-sized and large males, the spines become better 

 developed than in any of the females. Specimen 4 and all indi- 

 viduals of greater body length have spines on the ischium in 

 addition to the spines on the palm, carpus, and merus. Speci- 

 mens 7 to 14, inclusive, have also a few spines on the immobile 

 finger. The spines in this species are not conspicuous, being 

 broad, low, and subacute in old males. The "linear spaces" 

 cannot be distinguished. There are very minute spines present 

 on the merus, carpus, and propodus of the third, fourth, and 

 fifth legs, but these can only be seen in the old males. 



Eggs. — The eggs of this variety when preserved measure from 

 0.5 to 0.7 by 0.7 to 1 millimeter. Those of P. lanceifrons measure 

 from 0.5 to 0.7 by 0.6 to 0.8 millimeter. The eggs of both are 

 smaller than those of Palaemon elegans de Man, which measure 

 1 to 1.1 by 1.4 to 1.5 millimeters. 



Color of the living specimens. — The color of the general sur- 

 face of the body is similar to that of Palaemon lanceifrons Dana. 

 The pigment marks which are so characteristic of the carapace 

 of the latter are plainly seen. 



Localities. — There are 37 males and 35 females of this variety 

 in our collection; all of them were collected below the dam at 

 Montalban near Manila. 



