163 



$ ? 



Length of second pair of legs, . . 167 millims. 39 milliras. 



" " third pair of legs, ... 65 " " 



" " manus of first pair, 60 " 10 " 



" " carpus " ... 55 " 13 " 



" " meros " ... 35 " 16 " 



Notwithstanding the great difference in the proportions of the 

 joints of the second pair of limbs in the males and females, I think 

 there is no doubt they belong to the same species, since they were 

 taken on the same occasion, and in other respects resemble each other 

 closely. 



In every point except those mentioned above, my specimens agree 

 with Streets' description and figure, yet they are from the western 

 shore of the Gulf of California, while his specimens were from Coat- 

 zoalios River, Isthmus of Tehuantepec, and the species has always 

 been known as an Atlantic one. Yet the differences are so small as to 

 be, in iny opinion, only varietal, and a parallel case occurs in the 

 genus Alpheus, where A. hetcrochelis and A. minus are common to both 

 the Atlantic and Pacific shores. 



Pontonia margarita S. I. Smith, Am. Naturalist, 1869, vol. Ill, 

 p. 245, foot note. 



This species, originally described from individuals collected at Pan- 

 ama, was taken in considerable numbers at Port Escendido, Mulege 

 Bay and Gulf of California, by W. I. Fisher, in August, 1876, at which 

 date the females were with spawn. 



The color after a month in spirits, was a light rose tint, with occa- 

 sionally some dark markings upon the hands. 



The specimens agree in every respect with Smith's description, and 

 inhabited the same shell, viz., Margarit ophora fimbriata. 



Pontonia pinnse nov. sp. 



Body slightly depressed; carapax smooth, rostrum elongate-trian- 

 gular, deflected, the tip lying between the base of the antennulse; 

 antennal spine prominent. 



Peduncles of eyes short, broad ovate, cornea much narrower than 

 the peduncle. 



Peduncle of antennulse exceeding the rostrum by the length of its 

 distal joint, flagella not longer than the two last joints of the peduncle 

 subequal, the outer stouter than the inner. 



Antennal scale broad, as long as antennular peduncle, antennal fla- 

 gellura extending backwards to about the middle of the carapax. 



