[13] MEDUSje FROM THE GULF STREAM. 939 



30-50™"> long, and is united to the walls of the snbuiubrella on a double 

 liDe, forming a figure shaped somewhat like a Greek cross, the re-enter- 

 ing angles corresponding to the smaller or interradial sections {Ih. int.), 

 which are fused with the walls of the lower floor of the disk, forming 

 the "cathammal plates." As nearly as could be observed, the free lips 

 of the proboscis are smooth. The "phacellen" are in poor condition. 

 Flakes of purple or brown color in the interior of the stomach walls are 

 the only remains of them which are visible. 



The stomach cavity opens by four orifices into a circular sinus, which 

 lies in the corona. These openings are situated at the extremities of 

 the cross-shaped union of stomach walls and subumbrcilla. The coronal 

 sinus, sometimes called the intestine, lies between the musculus coro- 

 nalis internus and the upper walls of the corona, and sends out radially 

 twenty-two pouches of the peripheral organs. When a portion of the 

 musculus coronalis internus is cut through, as at one of the deltoid 

 muscles, the scalpel penetrates the coronal sinus. It is a ring-shaped 

 recess, upon the upper wall of which — the lower floor of the disk — a 

 ring-shaped groove, corresponding on the under surface of the corona to 

 the coronal furrow on the upper, is seen. The coronal sinus is marked 

 out on the upper wall iu such a manner that the axial portion is inclosed 

 above by a portion of the lower surface of the discus centralis, and the 

 abaxial by the lower wall of the internal corona. 



The twenty-two i)ouches which extend radially from the coronal sinus 

 to peripheral organs pass below, or in a natural position of the medusa, 

 above the musculus coronalis internus and the musculus coronalis ex- 

 ternus, and are separated laterally" by a pair of clasjDS {cl.), which 

 serve to bind these structures to the lower side of the disk. The clasps 

 lie iu the radii of the sense-bodies of the umbrella margin, while be- 

 tween the members of a pair there is a narrow tube which extends from 

 the coronal sinus to the vicinity of the sense body. The ultimate ter- 

 mini of this and the other jiouches were not traced. Our specimen was 

 not well enough preserved to follow out with satisfaction the minute 

 structure and course of these organs in the elaborate way that Hseckel 

 was able to do in J.. Wt/villii. 



Atolla Verrillii, sp. nov. 



CPlates IV and Y.) 



Eight specimens of an Atolla, which differs from the preceding as 

 well as from any known species, were examined. They have long and 

 narrow sense-socles, which are more or less quadrangular, almost car- 

 tilaginous in texture. The marking, on the exumbral side of the um- 

 brella, which separate the socles of the sense-bodies from those of the 

 tentacles and the inner corona, as already described, are not seen in any 

 of the specimens of A. Verrillii. 



Of the eight specimens some are mutilated, perhaps distorted or badly 



