GAMSIARID.K. 211 



the extremity of the peduncle of the superior, furnished with lonj^ 

 fine hail's. Cinuthoi>odu subetiual, fumLshed with a lew stilt' haire : 

 first pair ha^•ing the propodos long-ovate ; palm very obUque, 

 slightly concave, not defined, armed near the centre with a single 

 short, obtuse spine: second pair slightly larger than the first, 

 having the propodos longer and broader, and the palm less oblique, 

 but imperfectly defined. Pereiopoda furnished postenorly with 

 long fine hairs, independent of the short spines ; third pair of 

 pereiopoda shorter than the two posterior. Posterior pair of pleo- 

 poda having the rami subequal and longer than the preceding. 

 Length ^ths of an inch. 



Hah. Common in the larger streams round Philadelphia {Say and 

 Stimpson). 



The figure is from a specimen presented by Professor Say to the 

 British Museum. The description is also taken from that specimen, 

 and from one preserved in spirits, sent to me by Mr. Stimpson. In 

 both, the eyes are round (not reniform, as stated by Say). The 

 second pair of gnathopoda, in the specimen presented by Say, differ 

 fi'om the description in the text in being somewhat truncate ; but as 

 the general appearance is that of a defective organ, I have adhered 

 to Stimpson's specimen as being the more perfect. Say describes the 

 species as being fasciated with faint green, and the appendages as 

 similarly spotted. 



11. Gammarus multifasciatus. (Plate XXXVII. fig. 7.) B.M. 

 Gammarus multifasciatus, Stimpson, MS. 



Eyes reniform. Superior antennae having the first joint of the 

 pedimcle stouter and longer than the others ; peduncle of the in- 

 ferior antennae not longer than that of the superior. Gnathopoda 

 small and of the same form : second pair slightly the larger ; pro- 

 podos subovate ; palm convex, slightly oblique. Pu-st two paii's of 

 pereiopoda clean ; the last three thickly covered with fasciculi of 

 spines. Posterior pair of pleopoda having the rami short, obtuse, 

 and thickly fumirihed with hairs. Telson long, each division tipped 

 with one long and three short obtuse spines, and fumished on the 

 outer side with one and on the inner side with two obtuse spines 

 subapically tipped with a single cilium. 



Length -g^ths of an inch. 



Hah. Grand Manan (Stimpson). 



I am indebted to Mr. Stimpson for the specimen uf this species fiom 

 which the description and figure are taken. 



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