158 



TURNER. 



[Vol. II. 



The preparations at my disposal make possible the demon- 

 stration of these bodies not only in the Hexapods (Fig. i), but 

 also in the Decapods (Fig. 2), and in the Xiphosura, and in cer- 



C"¥V\ 



Fig. 4. — Section of Polynoe. 



tain Polychaeta (Figs. 3-5), etc. In the Polychacta the stalk 

 seems to be unbranched (Fig. 5), although in Nereis (Fig. 3) 

 and Polynoe (Fig. 4) there is a slight indication of a bifurcation ; 

 in the Hexapods (Fig. i) and the Decapods (Fig. 2) it is bifur- 



Fir,. 5. — Section of Lepidoiiotus. 



cated, while in Limidns (Fig. 6) it is ramose. Indeed, in 

 Limubcs it is so much branched that it simulates, in structure, 

 the vertebrate cerebellum. 



At present it is not possible to state whether these mush- 



