104 MICROSCOPICAL STUDIES. 



The family Plumularidae is represented by three genera in British 

 waters, Pliimularia, Aglaophenia, and Antennularia. The last 

 named is distinguished by the whorled arrangement of its character- 

 istically short or bristle-like branches. The two former are plu- 

 mously branched ; in Plumularia, the gonangia are scattered along 

 the branches and the stems ; in Aglaophenia, they are collected into 

 great basket-like structures, called corbulae, formed by the modifica- 

 tion of an entire branch or pinna. The arrangement of the nema- 

 tophores is also distinct in the two genera. 



EXPLANATION OF PL. VI; FIGS. I. TO "V. 



Fig. I. Natural appearance of fronds of a species of Plumularia 

 growing upon the extremity of a blade of Zostera. The 

 black buds are gonangia, attached to the creeping and 

 connecting stolon or hydroriza and to the lower parts 

 of the fronds. (Original). 



Fig. II. A young frond, greatly enlarged, showing polyps in various 

 positions, and also the position of the nematophores (n) 

 both below and above the hydrothecae, and in the axils 

 of the branches ; dh. developing hydranth ; dhc. deve- 

 loping extremity of the stem or hydrocaulus. (Original). 



Fig. III., IV. and V. Various stages in the history of a gonangium ; 

 o. ova. (Original). 



Fig. VI. Shows two nematophores of another species, n. the 

 chitinous sarcotheca, emitting the highly extensile 

 whip of sarcostyle (after Hincks). 



STUDY XXII. THE EGGS AND YOUNG OF CEPHALOPODS. 



In the Cephalopods, we see the highest development of the Mol- 

 lusca, a superiority at once obvious when we consider their powers 

 for rapid locomotion, their powers of offence, their keen vision, and 

 the large size of their central nervous mass, the brain. In their 

 development, this vast gap that separates them from their fellows in 

 the common phylum, is emphasized strongly. Lamellibranchs, 

 marine Gastropods, &c., have all one characteristic larval form, the 

 veliger a tiny, free-swimming larva propelled by powerful cilia, 

 and housed in a transparent shell. Among Cephalopods no trace of 

 this is seen. 



Of the species found upon our coasts, the large Loligo Forbesii 

 deposits her eggs in masses of candle-shaped cocoons, attached at one 

 end to seaweed or other objects. This spring, on one occasion, we 

 found a considerable number of cocoons attached to the buoy rope of 

 a lobster pot (Plate VII., Fig. A), from which they hung in bunches, 

 recalling the primitive "dip" candles of auld lang syne. These 



