CYDIPPIDJE. 



29 



flappers. The pigment-spots become smaller and less conspicuous with 



Fig. 36. Fig. 37. 



advancing age. 



This species is exceedingly common in Eastport harbor, during the 

 month of September. 



Arctic Ocean (Mertens, Scoresby) ; Baffin's Bay (Fabricius) ; Massa- 

 chusetts Bay, and Eastport, Me. (A. Agassiz). 



Museum diagram No. 3 after Alex. Agassiz. 



Family CYDIPPID^E Gegenb. (rest AG.) 



CydippidcE GEGENB. Archiv f. Nat., 1856, I. p. 196. 

 Callianiridce ESCH. (p. />.) ' Syst. d. Acal., p. 21. 1829. 

 Cydippidce AGASS. Cont. Nat. Hist. U. S., in. p. 293. 1860. 



PLEUROBRACHIA FLEM. 



Pleurobracliia FLEM. Phil. Zool., II. p. 612. 

 Cydippe ESCH. Syst. tier Acal., p. 29. 1829. 

 Cydippe LESS. Zooph. Acal., p. 104. 1843. 

 Pleurobracliia AGASS. Mem. Am. Acad., IV. 1849, p. 314. 

 Pleurobracliia AGASS. Cont. Nat. Hist. U. S., HI. p. 203. 1860. 



Fig. 36. Still further advanced Mertensia, seen from the broad side. 



Fig. 37. Young Mertensia about in the same condition as that of the preceding figure, seen 

 from the narrow side. The main branches of the ainbulacral system have lost the character of 

 pouches. 



