Order LucernaricE. 539 



principal muscles of the disc broadly ligulate, gradually 

 widening from their proximal ends to the termination of 

 the arms where they are as broad as the tentacular tufts : 

 marginal muscle very broad and very thin, doubled longi- 

 tudinally, and, projecting considerably beyond the margin 

 of the aboral side, completely hides from direct view the 

 marginal anchors when the animal is looked at from the 

 oral side ; it suddenly thins out to a mere film at the bases 

 of the tentacles : gelatiniform layer of the aboral side quite 

 thick and uniform from the junction with the pedicel to 

 the margin where it abruptly terminates ; from its inner to 

 its outer surface equal to the basal diameter of the largest 

 tentacles ; in the pedicel exterior to the cameras it is one 

 quarter thicker than in the bell, but no thicker than the 

 latter in the base ; between the four apertures of the pedi- 

 cel cameras, it projects considerably in the form of a boss, 

 from which a thick ridge extends to the proximal end of 

 each partition ; the fibroid bodies arranged very much like 

 those in Halichjstus auricula : lasso-cell groups or pockets 

 scattered here and there over the oral side. Size ; bell one 

 quarter of an inch in diameter, and three eighths of an 

 inch high including the pedicel. Geographical distribu- 

 tion ; a single specimen was found in September, 1862, at 

 Chelsea Beach, Mass., along with Haliclystus auricula^ 

 attached to Zostera marina^ at half tide. 



Craterolophus.* H. James-Clark.t 



Disc octohedral, campanuliform ; arms produced ; pedicel 

 monocamerous, the camera possessed of ridges which form 



* KpaTTjp, a cup ; ?i6(j>og, a tuft. 



t A species of Lucernaria from Heligoland described by Jlettenheimer. Ueber 

 den Bau iind das leben einiger wirbel. Thiere, &c. Abhandl. Senkenberg. Naturf. 

 Gesell. Frankfurt, 1854, p. 15, plate I. fig. 5-11, is generically unlike any other, ex- 

 cept, perhaps, the Lucernaria convolvulus, Johnston, and therefore for the sake of 

 uniformity, I am obliged to characterize a genus, without having seen the ani- 

 mal, and from the written description of Mettenhcimer. 



