﻿348 The Philippine Journal of Scieri e 



(33.5 millimeters) ; in specimens from 90 to 96.' millimeters long 

 the tip of the rostrum barely reaches the tip of ^ e antennal scale ; 

 in those from 96.5 to about 124 millimeters ' ong the r ° stru ™ 

 usually fails to reach the tip of the antennal scale b ^ f rom 

 to 3 millimeters ; and in specimens from 124 t> 144 m \ hmeters 

 long this distance usually increases to from 4 to 6 millimeters. 

 The specimen (111.5 millimeters) indicated in rable ll 1S a ma e 

 which has assumed adult male characters (you Ig mature male) ' 

 although its body is still only of medium lengt 1 ' lt 1S cover ^ d 

 with a dirty brown sediment, and its cheliped are enormously 

 developed relative to the body length. The ostr " m . ±alls t0 

 reach the antennal scale by 7.5 millimeters. 1 he £ .£•%*" 

 though much shorter than those of the specimen ^ m ] 

 long (Table II), are almost perfect miniatures sno ™g prac- 

 tically the same proportions. While the decreas e in ^ 

 length of the rostrum with reference to the a ntennal scale is 

 not so regular with increasing size as in the ioca 

 Palaemon cartinus, it is, nevertheless, plainly &i>i &r&n ' ... 



Curvature and dental formida of rostrum. — Sp 601 ™ 6118 ' 



ferent ages show such a remarkable difference r 11 . s c ^ 

 the rostrum, that if I had not seen all of my s ? eCimen Ytne 

 alive I should hesitate to consider them as be' ongll \ g f 



same species. In this respect P. philippinensis ? emi ^ s .,. , 



the variable form of the rostrum in P. weberi < , . 



iflv IcinoTS men- 

 P. dispar von Martens. 2S Certain characteristic b . 



tioned under the section devoted to the color of. l . 



dividuals and not found in any other species in ,°^ r Q Q°r •«• 



were present in all. The youngest males (33.5 a^ ' * 



meters) and the youngest females (47 to 71.5 milli me e] 



the dorsal border of the rostrum almost straight,' °" y a .. 



slight convexity over the eye being apparent. A^ e 



feminises" (those similar in general appearance to , ema . 



females increase in body length, the convexity becorj ( ^ s .^ 



more pronounced. In the largest males it is very 



in the largest females it is not so much so. Th« a 2 ^ 



middle-aged males which take on the adult charaCj .f 



show a greater curvature of the dorsal border of c 



over the eye than do the "males feminises" of thti' 



Correlated with this increase in the convexity, as the^ e 



27 Zoologische Ergebnisse einer Reise in Niederlandiseh Ost-i 

 2, 421. j c 



"Arch. f. Naturgesch. (1868), 5, 41. • 1 



