354 The Philippine Journal of Science wu 



length reaching beyond the tip of the telson. This condition 

 figured by Ortmann. 32 In older specimens (Plate II, fig. 2k), 

 however, the tip, the externolateral spine, and the internolateral 

 spines are proportionally much shorter. 



Character of surface. — All females and all "males feminises," 

 with the exceptions of Nos. 20 and 22, present no areas of spi- 

 nules on the carapace, telson, or abdominal somites. Nos. 20 

 and 22 are slightly rough to the touch along the anterior part 

 of the carapace. All of the young mature males and the old 

 males show the characteristic areas of spinules described above 

 for the largest male specimen. 



Eggs. — The eggs of P. philippinensis, when preserved, measure 

 about 1 by 1.3 millimeters. 



Color of living specimen. — Palaemon philippinensis is not 

 brilliantly colored. The surface is translucent, showing an 

 underlying ground color of gray which is usually punctated 

 on the dorsal and lateral regions of the abdomen and carapace 

 with fine brownish red dots. The telson is usually bright 

 brownish red in color, although not conspicuously so. The fol- 

 lowing striking pigment marks which may be seen through the 

 translucent carapace are characteristic of the species (Plate II, 

 fig. 2m) : 



1. Two usually brownish black lines running longitudinally on each side 



of the dorsal median line of the carapace. 



2. A conspicuous T-shaped dark pigment mark seen on the posterior part 



of each gill cover. 



3. Usually a dark, obliquely placed pigment mark immediately back of the 



hepatic spine. 



The first and second antenna? are marked with brownish red 

 and show no blue color. Along the ventral border of the pleura 

 of the fourth and fifth abdominal somites is a purple band. The 

 first, third, fourth, and fifth legs are translucent and punctated 

 with reddish brown dots, while the chelipeds are dark in color 

 and marked longitudinally with dark greenish bands. The color 

 of the pigment varies somewhat in different specimens and also 

 probably in the same specimens at different times. The color 

 disappears almost entirely after preservation. In the young 

 mature males and sometimes in the adult males a covering of 

 brownish sediment often obscures the color, but the sediment 

 may be rubbed off, leaving the markings visible. 



Localities. — We have in our collection 31 males and 8 females, 

 all but one of which were taken in San Juan River (usually 



"Zool. Jahrb., SystemaUk (1891), 5, Tafel XLVII, Fig. 4. 



