62 OPHIUR^E. 



of the ray, but in general are not quite so long, being 

 about twice the breadth. These spines, when highly mag- 

 nified, present a very complicated structure ; and their 

 roughness arises from spine-like processes on their surface. 

 When the animal is alive, a membrane appears to web 

 these processes together ; but I have never been able to 

 observe anything like ciliary motions excited around the 

 spines. Between each row is a pinnated cirrhus, which 

 likewise does not appear to be ciliated. It is very flexible, 

 and can be withdrawn in great part within the ray. 

 Hound the mouth are twenty tentacula, ten external, and 

 ten internal, similar in structure to the cirrhi. The rays 

 vary in their proportions to the disk, but are usually from 

 four to five times as long as the disk is broad. The disk 

 generally measures in a fair-sized specimen about four- 

 tenths of an inch across. It is sometimes of a dusky rose- 

 colour, with gray scales ; sometimes white, spotted with 

 red, often marked with a star of red or yellow ; and occa- 

 sionally nearly black. The rays are generally white or 

 gray, banded with bright pink ; often of a deep blue, 

 with rose-coloured spines, or banded with bright yellow, 

 or speckled with brown and orange. The spines have 

 sometimes brown tips and blue bases. Little red spots 

 are often seen on each of the points of junction of the rays 

 beneath ; but as they are not constant, nor always of the 

 same form, I cannot regard them as ocular. When the 

 creature is in egg, the ovarian masses shine through the 

 body, giving it a yellow tinge between the rays ; they 

 are reniform and yellow, and transversely striated in con- 

 sequence of the arrangement of the round yellow eggs. 

 In the month of April, instead of eggs, I have often found 

 those masses filled with a milky fluid which, when mag- 

 nified, presents the spectacle of a great number of very 



