GAMMARin.K. J 1 i 



22. Gammarus pimgens*. 

 Ganininrus pnnpreus, Eihcurds, Hist, dvs Crust, iii. p. 47. 

 "Closely resembles G. marinus. Having: the inner ramus of the 

 posterior pair of pleopoda almost rudimentary, and the outer one 

 large and hairy." 



Hab. "Warm springs of Mount Cassini in Italy. 



23. Gammarus Atchensis. (Platk XXXVITI. fig. 7.) 

 Gammarus Atcheusis, Brandt, Sibirische Reise, pi. G. f. 29. 



Cephalon and pereion smooth. Pleon dorsally covered with short 

 spines ; first segment having a single row near the posterior mar- 

 gin ; second having two rows ; third having one row along the 

 posterior margin, and, anteriorly to it, two diagonal rows on each 

 side ; fourth having two diagonal rows on each side ; fifth having 

 one diagonal row on each side ; sixth not having any spines. Su- 

 jjerior pair of antennae .shorter than the inferior ; flagellum not 

 longer than the peduncle ; secondaiy appendage about half the 

 length of the primary. Gnathopoda subequal and of the same 

 form ; in each the carpus is nearly as long as the propodos ; pro- 

 podos half as long again as broad, palm straight, excavate near 

 the base of the dactylos, inferior angle rounded, unarmed ; dactylos 

 short, robust. Basa of the tkree posterior pairs of pereiopoda 

 round. Penultimate pair of pleopoda shorter than the preceding ; 

 posterior pair reaching but a short distance beyond the preceding, 

 rami unequal, the outer being broad and fringed with cilia, the 

 inner very small. Telson unai-med. 



Length nearly |- of an inch. 



Hab. Isle of Atcha. 



The description, as also the figure, are taken from a specimen in 

 the collection sent by Prof. Brandt to the Jardin des Plantes. 



24. Gammarus Maackii. (Plate XXXVITI. fig. 8.) 

 Gammarus Maackii, lirandt, 3Iiddendorff^ s Sibirische Reise. 



Pleon having the dorsal surface near the posterior extremity of each 

 segment armed with a few short strong spines. Eyes reniform. 

 Antenme subequal, one-third the length of the animal, having the 

 flagclla half the length of the peduncles ; secondary apjiendage 

 of the superior pair more than half the length of the primary. 

 Gnathopoda somewhat alike in form, but unequal in size ; second 

 pair larger than the first, having the propodos ovate, palm oblique, 



* This species appears closely to resemble a Niphargus. — C. 8. B. 



