258 CONTRIBUTIONS TO THE NATURAL HISTORY 



mass, the parts of the whole body in their natural position. Fig. 2 represents a speci- 

 men seen from below, looking into the main cavity of the body, with all the tentacles 

 fully drawn out, in order to show the lower opening, the mouth, and its tentacles, the 

 main digestive cavity, and the four rays which arise from it, and curve downwards to 

 reach the four bulbs, from which the tentacles arise. In this figure it is plainly seen 

 that the tentacles are inserted upon a triangular, or somewhat crescent-shaped bulb, 

 and that there is an eye-speck at the base of each on its lower surface. From this bulb 

 the tentacles diverge somewhat in the form of four bunches, and, on comparing this fig- 

 ure with the upper figure, it is easily ascertained that the tentacles are stretched up- 

 wards in such a manner as to form a sort of radiating arch stretching upwards and out- 

 wards, the bulb being then slightly turned outwards. Between the four bulbs, a canal 

 is observed assuming an almost quadrangular form, though its four sides are slightly 

 arched outwards. The respective position and relation of these parts are further well 

 shown in Fig. 1, where the large, central brown bulb represents the central digestive 

 cavity, which is nearly quadrangular, or almost cubical with prominent angles, and from 

 the lower corners of which arise four bunches of tentacles surrounding the mouth, which 

 last is placed in the centre of the lower surface, as seen in Fig. 2. The angles of the 

 mouth project in the same direction as the bunches of its tentacles, which are also devel- 

 oped in the same direction as the four ciiymiferous tubes arising from the upper corners of 

 the digestive cavity, so that the radiation of all parts takes place in the same direction. 

 These four radiating chymiferous tubes first rise upwards, and are then arched over 

 sideways, to turn downwards and finally meet the four sensitive bulbs below, following 

 in their course the inner surface of the gelatinous mass. This mass has a prominent 

 rounded discoid projection upon the centre of its lower surface ; thus causing the 

 central digestive cavity to hang, as it were, downwards into the main cavity of the 

 body, though in fact it arises, as in other genera of this type, upon the lower surface 

 of the gelatinous disk. But this surface being not uniformly arched, but prominent in 

 its centre, the parts seem to have here a very different arrangement; and, had it not 

 been ascertained, by a vertical section through the centre, that the middle portion 

 of the gelatinous disk bulges downwards, it might have been supposed that the 

 central digestive cavity was hanging loose below the disk, and was suspended to the 

 four radiating chymiferous tubes. 



The branching tentacles of the corners of the mouth hang downward, in their natural 

 position, as seen in Fig. 1. They are naturally foreshortened in Fig. 2, where they are 

 seen from below. The difference shown in these two figures in the form of the sensitive 

 bulbs and in the fringed eye-specks arises, also, solely from the position of the animal. 



