ix, d, 4 Cowles: Palaemons of the Philippine Islands 371 



pus, but these are only visible under rather high magnification. 

 In older specimens the spines are larger and cover the proximal 

 part of the immobile finger, the palm, the carpus, the merus, 

 and the ischium. The spines on the chelipeds are inconspicuous, 

 being broad, low, and subacute. "Linear spaces" cannot be 

 distinguished. Very minute spinules may be seen, with the aid 

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

 and fifth legs. 



Eggs. — There are no females of this form in the collection. 



Color of the living specimens. — The color of these specimens 

 agrees with that of the typical Palaemon lanceifrons Dana, the 

 pigment marks on the sides of the carapace being plainly visible. 



Locality. — All of these specimens were captured in San Juan 

 River near Manila. 



Palaemon lanceifrons Dana var. montalbanensis var. nov. Plate II, 

 figs. 6 and 6a-i. 



I have collected from the water supply of the city of Manila 

 at Montalban 72 specimens of a form which I consider to be 

 a variety of Palaemon lanceifrons Dana and one which in some 

 respects is very similar to Palaemon elegans de Man. It is char- 

 acterized by the decided convexity and shortness of the rostrum, 

 by the fingers being much shorter than the palm in large speci- 

 mens, and by the presence of tubercles in older males along 

 the sides of the cutting edge of the fingers. 



This variety, which I have called P. I. var. montalbanensis, 

 differs from P. lanceifrons as originally described by Dana in 

 the following particulars: The number of teeth on the dorsal 

 and ventral borders of the rostrum is less, the rostrum does not 

 extend so far forward, and the carpus is considerably shorter than 

 the propodus even in young specimens. 



Palaemon lanceifrons var. montalbanensis, while very similar 

 to P. elegans de Man, differs as follows : The number of teeth on 

 the dorsal and ventral borders of the rostrum is less ; the teeth at 

 the distal end of the dorsal border of the rostrum are spaced more 

 widely ; the chelipeds are unequal in length except in the young ; 

 the relative length of the fingers and palm of the chelipeds is 

 different; the segments of the chelipeds are thicker; and the 

 tubercles along the sides of the cutting edge of the fingers are 

 distributed differently. Judging from the 37 males and 35 fe- 

 males in our collection, the mature females are much smaller 

 than the old males. 



The following description applies to the large male listed as 

 No. 12 in Table V. This specimen, which measures 65.5 milli- 



