NATURAL HISTORY SOCIETY OF GLASGOW. 63 



nest, and sometimes among the loose coral outside of it, but 

 we do not remember ever observing it in any other situation. 

 It always accompanies the Lima. 



It is a greenish-yellow looking worm, the colour being derived 

 from the green blood which is conspicuous in the gills. It does 

 not form any tube of its own, but crawls over the inner surface of 

 the nest. To the eye, it appears to be enclosed in a sort of loose 

 bag, to which it is attached by narrow cross lines — these are the 

 bristles of the feet, and are consequently opposite to each articu- 

 lation. These bristles pass to this loose external integument, and 

 project a little beyond it. The intervening space between each 

 bristle, that is, between each pair of feet, is filled up by a close 

 band of fine hairs, each of which is swollen at the extremity — the 

 "polls renfl^s" of Quatrefages. They resemble filiform curled 

 filaments, each attached to a fusiform body, and are not unlike a 

 large thread-cell with the thread discharged. These peculiar hairs 

 approach more or less towards the margin of the loose external 

 envelope, some of them quite up to it, and are found in this 

 situation all over the body of the animal, and even in the green 

 concave fans. These are placed on each side of the head, and are 

 composed of numerous bristles. When crawling over the nest of 

 the Lima, the loose external skin gives it very much the appear- 

 ance of being enclosed in some sort of jelly. 



This species does not seem to be S. uncinata, which, according 

 to Quatrefages, has the body naked, and without the " polls." 



In addition to the Asteroidea already named as occurring in these 

 localities, OpMura texturata, often of a large size, will be found; also 

 0. alhida, Cribella oculata, Amj^hidotus cordatus, Echinus miliaris, and 

 E. sphmra. Pentadapentades and Syrinx nuda have been got, and the 

 dead shells of Denkdium frequently contain a species of Sipunculus. 



So far as one can see, the shell of the male Echinus does not 

 present any perceptible difference from that of the female, but to 

 the eye of an urchin some peculiarity must undoubtedly exist 

 between the two. The curious larval form, Plutens, somewhat 

 resembling a painter's easel, and so remarkably dissimilar to the 

 future spherical shell of the urchin, we have only seen by chance 

 under the microscope, when examining some luminous or phos- 

 phorescent water taken near the shore. After observing several 

 of the Protozoa, so abundant when sea water presents that appear- 



