84 URASTERIyE. 



The Common Crossfish has generally five rays, occa- 

 sionally six, and not nnfreqnently as few as four. The 

 rays are rounded, and taper gradually to a point. They 

 are commonly about three and a half times as long as the 

 disk is broad, and the breadth of each is somewhat less 

 than a third of its length. Both disk and rays are reti- 

 culated, and at the angles of the reticulations arise conical 

 blunt spines, the bases of which are surrounded by circles 

 of thickly-studded spinules. The spines generally form a 

 more or less regular keel on the upper surface of each ray, 

 and sometimes an irregular circle round the disk. In the 

 spaces between the reticulations are numerous small, cleft, 

 pincer-shaped, flattened, pedunculated spinules. Beneath, 

 the avenues taper according to the shape of the rays, and 

 are not so contracted at their origins as in the next species. 

 The edges of each avenue are bordered, first, by thickly- 

 set, long, thin, tapering spines, which have frequently 

 several spinules projecting in a radiant manner from their 

 inner side near their tips. Next to these are transverse 

 rows of stout spines, similar to those on the rays above, 

 but larger and stronger. There are generally three in each 

 row, and their bases are surrounded by tufts of spinules. 

 At some distance from these spines bordering the upper 

 surface of the ray is a row of similar spines, not so thick 

 or strong, placed longitudinally in pairs. At the extremity 

 of each ray we find the eyes surrounded by a circle of move- 

 able spines, not different from the ray-spines near them, 

 either as to form or size. The mouth is protected by spines 

 of a similar nature with and but little longer than those 

 forming the immediate edging of the avenues. The suckers 

 are cylindrical, nearly equal in thickness throughout their 

 lengths, and furnished with globose extremities. They are 

 very extensile, especially those near the extremities of the 



