424 [Proc. B.N.F.O., 



Mr. Galway read a paper entitled a "Chat about British 

 Star Fishes," and in introducing his subject said that the 

 Echinodermata constituted one of the great classes of animals, 

 and are characterised by a radial symmetry rather than 

 bilateral symmetry. The comparative anatomy, embryology, 

 and palaeontology point to these animals as having derived 

 their radiate form, ambulacra, and the coil of the gut through 

 having passed through a "pelmatozoic" stage in which the 

 mouth faced upwards, the animal being attached by part of its 

 body-wall. Star-fish are covered with a coriaceous skin, which 

 is strengthened by a beautiful net work of calcareous plates, 

 and are highly organised. The water vascular system of the 

 radiate type is characteristic of the group, and is quite unique 

 in the animal kingdom. The water circulating through a 

 system of sacs and tubes is carried by five radial canals through 

 the body, which enable the tubular sucking feet to- act as 

 organs of progression and respiration. On dissection a tube 

 foot is found to divide at its base intO' two branches, one pass- 

 ing into a closed sac, and the other into a large tube which 

 runs from the tip of the ray, receiving in its course similar 

 branches from all the other tube-feet in each ray ; this large 

 tube again opens intO' a circular tube surrounding the mouth, 

 and which leads through the Madreporic canal, a curved cal- 

 careous column running obliquely up to the surface, and ter- 

 minating in the Madreporite, a wart-like body found on the 

 surface of the true star-fishes. The water vascular system was 

 explained by means of a diagram, showing the different tubes 

 with their sucking feet attached. Exceedingly minute and 

 beautifully formed pincer-shaped organs found on star-fishes 

 and sea-urchins are the pedicellariae. These are merely 

 modified and elaborated spines. No' class of invertebrate 

 animals appear tO' have been better represented during past 

 epochs than the Echinoderms, and in the case of the Crinoids 

 immense masses of rock are formed from their remains, in 

 Derbyshire large beds of marble being mainly composed of the 

 broken stems and heads of the crinoids or stone-lilies. A short 

 sketch was given of the structure and principal characteristics 



