CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA 37 



at Harvard College, vol. 39, p. 267, plate 8, fig. 30.) Also Chun, 1880 

 (Ctenophoren des Golfes von Neapel, p. 242), found yellowish-green para- 

 sitic cells of algae in the meridional canals of Euchlora which resemble 

 the yellow cells of Radiolaria. 



The histologic structure of the papillae of Leucothea is described by 

 R. Hertwig, 1880, Jena. Zeit. fur Naturw., Bd. 14, p. 334, Taf. 21, Fig. 3. 



Genus OCYROPSIS (nom. nov.). 



Ocyroe, preoccupied in 1809, for medusae by Peron and Lesueur. 



Ocyroe, Rang, 1828, M6m. Soc. Nat. Paris, tome 4, p. 172. — Lesson, 1836, Annales 

 des Sci. Nat., s^r. 2, tome 5, p. 250. — Fewkes, 1882, Bull. Museum Comp. 

 Zool. at Harvard College, vol. 7, p. 252. — Chun, 1880, Ctenophoren des Golfes 

 von Neapel, p. 290. — Moser, 1903, Ctenophoren der S^'feoga-Expedition, p. 17, 

 also, 1908, Abhandl. Akad. Mtinchen, Suppl. Bd. i, AVjhandl. 4, p. 65. 



Calymma, Eschscholtz, 1829, Syst. der Acalephen, p. 33. — Mertens, 1833, M^m. 

 Acad. vSci. St. Pdtersbourg, Sci. Math. Phys. et Nat., s^r. 6, tome 2, p. 508. 



Calymma, preoccupied in i8i6 for Lepidoptera by Hubner. 



GENERIC CHARACTERS. 



Lobatae with body laterally compressed in the funnel-diameter and 

 with large, muscular oral lappets. These lappets arise from the sides 

 of the body in the stomodaeal axis, and it is mainly by means of their 

 contractions that the animal is enabled to swim. The ciliated combs 

 are not very numerous and in the young animal they tend to lie parallel 

 with the meridional canals, as in Cesium. In the adult, however, they 

 usually lie diagonally across the canal. The auricles are well developed 

 and arise from the body near the sides of the oral lappets. There are no 

 tentacles in the adult and no tentacular canals. 



Three species, O. crystallina, O. maculata, and 0. fusca are described 

 by Rang from the tropical Atlantic. O. crystallina is transparent; 0. fusca 

 uniform dull brown, and O. maculata has 2 large, conspicuous, brown 

 spots on each oral lobe. Eschscholtz, 1829, describes a form of Ocyropsis 

 from the Equatorial Pacific under the name Calymma trevirani. 



Ocyropsis bears some resemblance to De'/opea of the Mediterranean, 

 but the oral lobes of De'/opea are smaller and the two meridional ventral 

 vessels in each lobe end blindly, whereas they form a closed circuit in 

 Ocyropsis. Also De'iopea has tentacles, and these are absent in Ocyropsis, 

 wherein there are neither tentacles nor tentacular canals. 



The genus is found only in the tropics, being represented in both 

 the Atlantic and the Pacific. 



Unforttmately, the old and well-known generic name Ocyroe can not 

 be retained for Ctenophorse, for it was applied to a medusa by Pdron and 

 Lesueur, 1809 (Annales du Museum, Hist. Nat., Paris, tome 14, p. 354). 

 The name Calymma given to this ctenophore by Eschscholtz, 1829, is 

 also preoccupied, having been used by Hubner for Lepidoptera in 181 6. 

 While we must all regret the abandonment of long-used and familiar 

 generic names, yet the law of priority, which the zoologists of the world 

 have in congress assembled given their pledge to support, obliges us to 

 revert to the oldest distinctive name; and as preoccupied names must 

 be abandoned, no matter how familiar to us in association, it is expedient 

 that the operation of changing them be executed at once. In place of 

 Ocyroe I propose the new name Ocyropsis. 



