34 CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA 



long, however, as in M. leidyi and do not quite reach to the level of the 

 apical sense-organ. The 4 meridional ventral rows of combs which ex- 

 tend out over the oral lobes are about one-third longer than the 4 rows 

 which lead to the auricles. The meridional ventral rows begin also at a 

 greater distance from the apical sense-organ than do the meridional sub- 

 tentacular combs. The windings of the meridional ventral canals in the 

 oral lappets are very simple, thus differing markedly from the conditions 

 seen in M. leidyi and M. mccradyi. The apical sense-organ is sunken 

 within a deep cleft about one-sixth as deep as the total length of the 

 body. 



The surface of the oral lobes and the adjacent parts of the body 

 are besprinkled regularly with small, low, discoidal warts. The animal 

 is translucent and shghtly bltiish in color. It is very abundant along the 

 coast from Chesapeake Bay to Florida, being especially common in bays, 

 sounds, and estuaries where the water is slightly brackish. 



I have never seen any intergrading forms between this southern 

 species and the somewhat more northerly M. leidyi. M. leidyi is a 

 creature of the pure sea-water along the outer shores, while M. gardeni 

 thrives in protected bays and brackish waters. 



Genus LEUCOTHEA Mertens, 1833. 



Eitcharis, preoccupied by Latreille for Hymenoptera in 1804. 



Eucharis, used for Mollusca by P6ron in 1807. 



Eucharis, Eschscholtz, 1825, Isis, p. 742; also, 1829, Syst. der Akal., p. 31. — 

 Chun, 1880, Ctenophoren des Golfes von Neapel, p. 296. — Agassiz and 

 Mayer, 1899, Bull. Museum Comp. Zool. at Harvard College, vol. 32, p. 176. — 

 Allman, 1882, Journal Linnean Soc. London, vol. 16, p. 103. 



Beroe, Quoy et Gaimarp, 1824, Voyage de I'Uranie, Zool., p. 574. 



Alcione, Delle Chiaje, 1829, Mem. Animali senzavert., Napoli, tome 4, p. 7. 

 Ibid., 1841, Tav. 150. 



Leucothea, Mertens, 1833, M6m. Acad. Sci. St. Petersbourg, Sci. Math. Phys. et 

 Nat., ser. 6, tome 2, p. 499. 



Chiaja, Lesson, 1843, Hist. Zooph. Acal., p. 77. 



GENERIC CHARACTERS. 



Lobatse in which the oral lobes are of large size and contain com- 

 plexly-winding chymiferous tubes. The auricles are long, thic'k, and 

 coiled in helices with the cilia extending in a loop up and down one side. 

 The outer surface of the body and lobes are covered with long, conical 

 papillae. The aboral blind ends of the subtentacular meridional canals 

 are long. The 2 median tentacles are very long; 2 long, blindly ending, 

 pit-like depressions extend inward from above the tentacles nearly to 

 the level of the funnel. 



This genus is descended from a Bolinopsis-like ancestor, for it passes 

 through a stage in which it can not be distinguished from Bolinopsis. 

 The large papillae which cover the external surfaces of the oral lobes and 

 of the body are late in developing and do not appear until the animal 

 has passed through the Bolinopsis stage. In this connection it is interest- 

 ing to observe that Bolinopsis elegans of Mertens, 1833, is covered with 

 small papillae on the whole outer surface of its body, save only upon the 

 lower parts of the oral lobes. 



The name Eucharis is preoccupied, having been used for Hymenop- 

 tera by Latreille, 1804. Alcinoe of Delle Chiaje, 1829, can not be used. 



