mrdi^s.t:. 41 



into a very Inoail adhosivo ilisc, liy wliich the animal fixes itsolf to tlie bottom of the 

 sea. There h no true stalk, and only a narrow constriction separates the umlirella 

 from the adhesive disc. The peduncle is hollow and consists of one .single chanilier, 

 which is partly filled up with the bulbous enlargements of the four taeniola;. The 

 internal longitudinal mu.scle bands of the ticniola terminate at the constriction, and 

 do not proceed into the peduncle itself. In the peduncle the tivniolae are wholly 

 gelatinous, as in Lucernariit campanulata. The jelly or raesoglaea on the bottom of the 

 peduncle and of the taeuiola is permeated by small branched canals which come from 

 the hollow chamber. The ectodermal surface of the peduncle is divided up into 

 numerous small lobes and irregular folds, which arc flattened out on the side used 

 for attachment. 



The mouth has a large, thin, leaf-like margin which is beautifully arranged in folds. 

 It opens through a small constricted esophagus into the stomach, which is rather 

 .small for the size of the umbrella, and is well packed with gastric filaments. The 

 funnel cavities are large and penetrate about half the lengtli of the stomach. The 

 gastric filaments are very much crowded together on the tseniolae. As a rule they are 

 branched close to their base, and occasionally near their distal ends. They have the 

 appearance of flat slender ribbons, about 5 to 10 mm. in length. 



The arms are short and thick, and are about equal distances apart. Upon eacli 

 arm is situated a large oval cluster of short capitate tentacles, the number of which is 

 estimated up to about three hundred. The capitate apex of the tentacle is crowded 

 with long nematocy.sts. The tentacles forming the outer row, on the ex-umbrellar side, 

 are provided with a lateral adhesive pad (Plate V., fig. 4), and some of the tentacles 

 in the second row have also similar pads. Lucernaria campanulata has adhesive pads 

 of similar structure on the tentacles occupying the same position as those of Lucernaria 

 vanhoefeni. 



The gonads extend from the stomach to the base of the arms, forming fairly broad 

 band.s. Each band consists of a large number of elongated sacs (Plate V., fig. 5). 

 Transverse and longitudinal sections were cut of the sacs, but only a diagram 

 (Plate v., fig. 6) of their structure is given, as the preservation was too bad for the 

 drawing of an actual section. Each .sac consists of a large number of little branched 

 or unbranched tubes, lined with endoderm and .separated from one another by 

 mesoglsea. All the tubes are connected with a main duct, which runs the whole length 

 of the sac and opens at one end to the exterior. The blind end of the tubes is blocked 

 with cells, amongst which .small ova are clearly visil)le. It is amongst these cells at 

 the end f)f the tubes that the gonads develop, and when the ova reacih a certain size 

 they pass down the tubes into the main duct which opens into the gastric pouch. In 

 the male the .small tubes are not .so well defined. There are mas.ses of sperm mother- 

 cells, which are connected with tubes leading i»ito a large broad duct filled with 

 spermatozoa. The structure of the gonads of Lucernaria vanhoeffi'ni is similar to that 

 dcscrilicd by Antipa for L. inilferi. 



