128 AMPrriPODA normalia. 



florsally produced and elevated into a tooth. Third segment of 

 the pleon luiving the posterior margin laterally produced into a 

 tooth near the centi'c, and also at the infero -posterior angle. 

 Supi>rior antonnic having the flagcllum longer than the peduncle ; 

 inferior anten7ino shorter than the superior. Gnathopoda uniform ; 

 cari)i longer than the propoda; propoda ha^^ng the palm short ; 

 dactyla longer than the palmoe ; coxaj deep, not produced to an 

 angle. Second pair of pereiopoda having the coxa produced to a 

 point, but not dii-ected posteriorly ; posterior mai'gin having a 

 tooth near the centre. Third pair of pereiopoda produced to an 

 angle directed downwards. Three posterior pairs of pereiopoda 

 ha\dng the bases angularly developed posteriorly. Three posterior 

 pairs of pleopoda subequal ; rami equal. Telson deeply divided. 

 Length -^ of an inch. 



Hah. Igoolik, Polar Sea {^ir John CJarh Ross) ; Greenland 

 (Fahrichis, Kroyer) ; Nantucket Island, N. America, 35 fathoms, 

 gravelly bottom (Stiinpson). 



Mr. Stimpson describes this species as " very beautiful in coloration, 

 which consists of deep pink annulations, one to each segment of the 

 body, on a yellowish-white ground. The anterior half of the ring is 

 thus pink, and the posterior half white. The last pair of eoxce are 

 conspicuously coloured. The anterior halves of the antennae are red." 



For the correctness of the above descrij)tion I am dependent 

 upon the figure given in the Appendix of the Second Ai'ctic Voyage 

 of Sir J. C. Ross, which can be accepted with confidence, it having 

 been di'awn from nature by Prof. Owen. On comparing it with the 

 more crude figure of Amjyhitoe Sen-a in Kroyer's ' Gronlands Amfi- 

 poder,' I can discover no specific distinction ; but this opinion must 

 necessarily be received with caution, since it is formed upon drawings 

 only. 



Not having been able to meet with Otho Fabricius's work above 

 quoted, I am indebted to Mr. Stimpson for the assertion that Oniscus 

 serratits of that author is synonymous ■with Amphitoe Serra of Kriiyer. 

 M. J^rilne-Edwards is of opinion that Ampliitoe Serra, Kr., is pro- 

 bably identical with Oniscus Cicada of 0. Fabricius (?. c. j). 258). 



3. Acaiithonotus Sayi. 



Anipliitoe seiTata, S'li/, Proc. Acad. Pkilad. i. pt. 2. 

 i:dw. Hist, dcs Crust, iii. p. 42. 



As well as I can judge from the inadequate description of this 

 species given by Prof. Say, it belongs to this genus. From the 

 two preceding species it only appears to be distinguished by having 

 " three efiuidistant spinose teeth " upon the palm of each pair of 

 gnathopoda. The name serratus being preoccupied, I have taken 

 upon myself the responsibility of changing it. It is named after 

 Prof. Say, in order that the species may continue to be associated 

 with its oricinal dcscriber. 



