ON THE LABORATORY OF THE MARINE BIOLOGICAL ASSOCIATION. 471 



cell lying in the anterior portion of the lateral mass of ganglion cells in 

 the eighth thoracic ganglion was seen to give off a moderately fine fibre, 

 which divided into two branches, one branch passing immediately out of 

 the ganglion through tlie anterior nerve-root, whilst the other ran for- 

 wards along the ganglionic cord. The forward branch pursued a perfectly 

 straight course until it reached the third thoracic ganglion, where it gave 

 off a branch passing out through the posterior root of the ganglion, and 

 then continued to run forwards to the second thoraci6 ganglion, passing 

 out through its posterior root. Hence this element, the cell of which lay in 

 the eighth thoracic ganglion, supplied fibres to three nerve-roots belonging to 

 different ganglia, namely, the anterior root of Thorax VIII., the posterior 

 root of Tliorax III., and the posterior-root of Thorax II. A number of 

 additional elements were also found in the abdomen. These resemble in 

 a general way those of the thorax, and will be described in detail in a 

 paper which will be published in the ' Quarterly Journal of Microscopical 

 Science.' 



Ill, On the Eclbinoderin Fauna of Plymouth. By J. C. Sumner. 



On receiving the nomination to the British Association Table at 

 Plymouth, I went down in the early part of January with the intention 

 of working at the Echinoderm fauna of the neighbourhood. Unluckily, 

 during the greater part of the time the weather was too bad to permit of 

 any dredging or trawling being done outside the Sound. In consequence 

 the following list is largely compiled from specimens already in the 

 collections at Plymouth. One unnamed specimen in a bottle turned out 

 to be Amphiura Chiajii. It was taken two miles S. of the Bi-eakwater, 

 and I believe has not been recorded so far south before. 



Crinoidea : 



Antedon rosacea . 



Ophiuroidea : 



Ophiura ciliaris . 

 Ophiura albida . 

 Ophiocnida brachiata 

 Opliiocoma nigra 

 Ophiothrix fragilis 

 Amphiura elegans 

 Amphiura Chiajii 



Asteroidea : 



Astropecten irregularis 

 Lindia ciliaris 

 Hippasterias phrygiana 

 Porania pulvillus 

 Asterina gibbosa. 

 I'almipes membranacea 

 Solaster papposus 

 Henricia sanguiiiolenta 

 Asterias glacialis 

 Asterias rubens . 



Echinoidea : 



Echinus acutus . 

 Echinus miliaris . 

 Echinus esculentus 

 Spatangus purpureus . 

 Echinocardium cordatum 

 Echinocyamus pusillus 



C'on\mon. 



Common. 



Rare. [on sand. 



Once taken two miles S. Yealm Head 



Common. 



One taken two miles S. Breakwater. 



Rare. 



Not common. 



It )» 

 Very common. 

 Rare. 

 Common. 

 Rare. 

 Common. 

 »» 



Common. 



Fairly commoa. / 



jf 

 Rare. 



