118 BULLETIN OF THE 



nivxa. My astonishment was considerable when there was brought to 

 light an internal economy which reminded one rather of an orange than 

 of an Echinoderm. A horizontal cut, just above the joint of the radial 

 shields, disclosed a quantity of membranous partitions stuffed with a sort 

 of pulp and radiating in a confused manner ; while a vertical section 

 showed a cavity, which might be the stomach, surrounded by and com- 

 municating with a number of convolutions or blind-sacks. The matter 

 became clear only by giving up the idea that a strict correspondence 

 with known forms was to be looked for. 



Passing upward through the mouth of a Gorgonocephalus, and getting 

 above the mouth-papillae, d (Plate I. fig. 1), and tentacles, r, we come to 

 the usual contractile aperture, which may well be called the stomach- 

 sphincter, du. It is considerably wrinkled, or even a little papillose on 

 its border, and opens into a flattened cavity, the stomach, St. Thus 

 far, the structure is normal, but beyond this point all is novel. In- 

 stead of remaining simple, the stomach passes outward and upwaiti into 

 a number of membranous pouches, which, in profile, present a fluted 

 aspect, aS'^', St". Their outer ends are attached in three ways ; first, St", 

 they stretch upwards and are strongly fixed to the roof of the disk-wall ; 

 secondly, they reach horizontally and grow to the inner points of the 

 egg-bearing lobes, 8, 8 ; thirdly, they incline downwards, and are power- 

 fully attached at ten points encircling the mouth. Of these points five 

 are brachial, St' (Fig. 2) ; and five interbrachial, St. It is to the outer 

 open angle of the moutli-frames that the latter are attached, by a part 

 of the floor of the stomach, which is there much thickened, 8/ (Fig. 1). 

 Immediately above this attachment opens out the much folded and 

 fluted interbrachial stomach-pouch, St" (Fig. 2), which, at its outer end, 

 adheres to the inner points of the corresponding genital lobes; and, 

 above, grows fast to the roof of the disk. In like manner there is a 

 brachial attachment to the upper side of each arm, aS'^' ; and above it 

 opens a brachial stomach-pouch which has a similar shape, and is made 

 fast at corresponding places. From these ten points the attachment of 

 the stomach-floor is continued outward over radiating lines, respectively 

 across the interbrachial spaces and along the tops of the arms, quite to 

 the body- wall. This structure would divide the body-cavity in ten 

 radiating compartments completely separated from each other, were it not 

 that an open space exists between the inner point of each attachment 

 and the stomach-sphincter, 8/ (Fig. 1 ). This open space corresponds to the 

 ring-canal surrounding the entrance to the stomach of Ophiurans {inner 

 perihiPiiuU canal, Ludwig), but dift'ers in being a mere continuation of 



