266 THE CANADIAN NATURALIST. fSept. 



ventral surface of the disk ; and from a point situated a little before 

 the centre of the same surface five narrow channels, protected by 

 marginal scales, radiate and defurcatiug thrice, run out on the 

 rays and their branches, giving off short branchlets to certain 

 sacculate protuberances placed at regular distances. No pinnulae. 

 On the protuberances and on the rays the channels are open ; 

 but upon the disk, between their first bifurcation and their com- 

 mon starting-point, their marginal scales close over them, forming 

 a vault, so that the five channels are converted into covered ducts, 

 converging iiito a common subcentral aperture, concealed bent ath 

 the integument, and not visible from the outside. In the covered 

 parts of the channels T found masses, consisting of miscroscopic 

 Crustacea, larval bivalves, and other remains of the food of the 

 animal, apparently taken through the ends and open parts of the 

 channels, and on its way, through their covered parts, to the con- 

 cealed mouth. On the rays, near their tips, are seen some few 

 pores, perhaps indicating the existence of retractile organs. The 

 ventral surface is clothed with rather small, thick-set, irregular 

 whitish scalefe, among which, in certain places, some six or seven 

 larger ones are seen forming a rosette. Between the rays and their 

 bifurcations this scaly covering of the ventral surface extends back 

 pn to tbe dorsal surface, ending there with great regularity in 

 triangular spaces pointing to the centre of the disk. The 

 remainder of the dorsal surface of the disk end the I'ays, which, 

 by this arrangement, assumes the form of a regular star with five 

 broad dichotomous rays, is clothed with a soft and smooth brown- 

 ish skin. There is no trace of a calyx. In the centre of the 

 even dorsal face of the disk is seen a somewhat pentagonal space 

 studded with minute pores. 



To have the channels on the disk converted into tunnel like 

 passages leading to a mouth concealed beneath the integument is 

 a peculiarity hitherto not observed in any recent Crinoid ; but it 

 is, as shown by Professor Huxley and Mr. Billings, a character- 

 istic of the palaeozoic Crinoids and Cystideaus. The absence of 

 any indication of a calyx at once excludes Hjiponovie from the 

 former. Among the Cjstideans it recalls the genus Agelncrinites, 

 of Vanuxem, by the depressed form of the body, the scaly cover- 

 ing, and the flatness of the dorsal surface, devoid of anything like 

 a stem or peduncle, as also by the absence of pectinated rhombs 

 and of pinnulae. Branchlets running from the channels to saccu- 

 late protuberances ai'e found also in the genus Glyptocystites of 



