K. PHŒNIX. — GEN. CHARACTERS. 269 



with small irregularly papilla-lihe prominences, not more than 

 172 "1111. in height. These are evidently caused by the hydranth, 

 invariably contained in them, of a commensal Hydrozoa which 

 is harbored in the sponge- wall. The prominences were not 

 observed in the uppermost region of the body only ; whether as 

 the result of abrasion or not, could not be determined. Under 

 the hand-lens, their summits as also the free edge of the cuff 

 appear to be spiny (PL XI, fig. 3). The spines, protruding for 

 not more than half a millimeter, are found to be the distal rays 

 of certain specially developed dermal hexactins. 



Are the papilhe to be regarded as something of constant 

 occurrence in the species ? In consideration of what we know 

 about the relation of the Walieria species to the commensal 

 Hydrozoa (see anon, under W. leucharti), this question is possibly 

 to be answered in the affirmative. However, nothing like the 

 papillîc, or the peculiarly modified dermalia (PL X, figs. 25-27) 

 in connection with them, has before been described from 

 R. phoenix. 



The coarse parenchymal bundles, exposed on the external 

 surface, pursue a sinuous course in oblique or in nearly longi- 

 tudinal directions (PL XT, fig. 2). The bundles, more deeply 

 situated and exposed on the gastral surface, take a course which 

 is inclined to be transverse in direction, similarly as we have 

 seen in other species of the genus. 



In the upper part the principal bundles of the skeleton run 

 obliquely right up to the sieve-plate border, exactly as is to be 

 seen in the figure of E. phoenix given by Schulze in the Chal- 

 lenger Keport. 



Some bundles, but by no means all, extracted from the lower 



