122 



LAFCEA. 



LAFCEA Lamx. 



Xa/cea Lamx. Expos. Meth. 1812. 



Lafaa Agass. Cont. Nat. Hist. IT. S., IV. p. 351. 1862. 



Lafma A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 91. 



Atractylis Wright ; in Ann. & Mag., VIII. p. 129. 1861. 



CanipanuUna Van Ben.; in Bull. Acad, de Belg., XIV. No. 5. 1847. 



Laodicea Agass. {p- p. non Less.). Cont. Nat. Hist. U. S., IV. p. 350. 18G2. 



Lafoea calcarata A. Agass. 



Laodicea calcarata A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 350. 1862. 

 Lafma cormtta Agass. (non Lamx.). Cont. Nat. Hist. U. S., IV. p. 351. 1861. 

 Campamdaria dumosa Leidy. Mar. Inv. N. J. and R. I., p. 6. 

 Lafma cornula A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 91, Fig. 4. 



The Medusa of Lafcea described in the Contributions of Professor 

 Agassiz, Vol. IV. p. 351, was referred by him to Lafoea cornuta of 

 Lamouroux. Having, however, since that time found at Nahant a 

 young Medusa closely allied to the one to be here described, I am 

 inclined to doubt this identification, even though I have not observed 

 its Hydrarium, as I have done for the Lafoea of Naushon ; the absence 

 of pigment-spots at the base of the tentacles, and the diflferent number 

 of tentacles at the time when the mg.iu. 



Medusae are liberated from the repro- 

 ductive calycles, easily distinguishes 

 these two Medusae. The Lafoean Me- 

 dusa found at Naushon was also fol- 

 lowed in its more advanced stages, 

 till we could connect it with the 

 young of the Medusa before described 

 as Laodicea calcarata. 



The largest specimens observed 

 were an inch in diameter ; the bell 

 is perfectly transparent (Fig. 184), 

 and, were it not for the four dark- 

 3^ellowish ovaries, it would readily 

 escape notice ; they hang down like 

 short curtains in close folds, extend- 

 mg almost the whole length of the 

 chymiferous tubes, from the digestive cavity where they run into the 

 folds of its base (Fig. 185), to the circular tube ; the digestive cavity 

 is short, and the actinostome divides into four thin, convoluted folds, 

 projecting beyond the edge of the digestive cavity to twice its diam- 



Fig. 184. Adult Medusa of Lafoea calcarata ; magnified. 



