6 Sea Lilies. 



the arm, to five or three near the end, flattened joints. These 

 form the alternate branchlets or 'pinnules, tapering towards the 

 tip, grooved along the inner side, the rows curving upwards on 

 either side and tending to arch over the grooves of the arms. 

 Each joint of the pinnules bears on its upper and outer angle 

 a short projecting spine, so that the feather which the pinnules 

 form by pluming the central rachis of the arm, has an extremely 

 rich and pretty effect. 



Most unluckily, all the specimens of G. Gaput-Medusce which 

 have reached Europe have the soft parts destroyed, and the 

 disk, or upper surface of the body, more or less injured. From 

 the light which the structure of allied forms has thrown upon 

 such fragments as have from time to time remained attached to 

 the stronger parts of the skeleton, we are able, however, to 

 restore the missing portions with tolerable certainty. The 

 body is covered above by a membrane, uniformly tessellated 

 with irregularly formed flat plates. This membrane, after 

 covering the disk, dips into the spaces between the series of 

 radial plates, and, with the plates of the cup, completes the 

 body-cavity. The mouth is a rounded or pentagonal aperture 

 of considerable size in the centre of the disk, and is surrounded 

 by a ring of five triangular tooth-like plates, their angles meet- 

 ing in the centre. Only one known specimen (in the collection 

 of M. Michelin, in Paris) shows these oral plates, and that speci- 

 men is not in a satisfactory condition for examination. From 

 the analogy of the young of some other forms, some such ar- 

 rangement might almost have been anticipated in this species. 

 The mouth opens into a stomach surrormded by a dark mass of 

 liver, and a short curved intestine leads to an excretory tube 

 upon the surface of the disk, near the mouth. From the 

 mouth five, six, or seven deep grooves, bordered on either side 

 by a row of small square plates, run out to the edges of the 

 disk, and are continuous with the grooves on the upper surface 

 of the arms. They divide at each bifurcation of the arms, and 

 send branches along the grooves of all the arm pinnules. In 

 these grooves lie the vessels of the water- vascular system, which 

 is so characteristic of the Echinoderms. The radiating vessels 

 arise from a central ring round the throat, and in their course they 

 give off a most complicated and beautiful series of radial and 

 brachial tentacles and respiratory leaves. In the star-fishes 

 and sea-urchins, the class-mates of the Crinoids, the ovaries are 

 placed within the bod} r . In the Crinoids, or, at all events, in 

 most of them, and certainly in all the modern forms, they are 

 developed at certain seasons all over the arms, as separate little 

 sacs, full of eggs, beneath the water- vessel on the inner surface 

 of each of the pinnules. This " vegetativo repetition, " as it 

 has been called, of one of the organs, seems to indicate a lower 



