37S EXPLANATION OF THE PLATES. 



6a. Zepas fascicidaris, carina of, nat. size. 



6$. „ „ var. villosa. 



6c. „ „ ,, carina of. 



6d. Part of the membrane from one side of the pe- 

 duncle of Ze]jasfasciciilaris,with the ball removed, 

 showing one of the cement-ducts, and the orifices 

 through which the vesicular membrane forming the 

 ball has been secreted ; greatly magnified ; viewed 

 from the outside. 



TAB. II. 



1 . Pcecilasma Kamp/eri, (magnified two and a half times.) 

 la. „ „ carina of. 



2. Pcecilasma aurantia, (magnified two and a half times.) 



3. Pcecilasma crassa, (magnified twice.) 

 3a. „ „ carina of. 



4. Poecilasmajissa, (magnified five times.) 



5. Pcecilasma ebumea, (magnified five times.) 



ba. „ „ carina of, external view of. 

 be. „ „ „ lateral view of. 



bb. „ „ scutum, internal view of. 



6. Zickelaspis Warwickii, (magnified five times.) 



6a. „ „ transverse section of the top 



of the peduncle, showing 

 the deeply-notched end of 

 the inwardly bent carina ; 

 magnified five times. 



6b. „ „ var., scutum and tergum. 



7. Dichelaspis pellucida, (magnified five times.) 



7a. ,, „ basal end of carina of, much 



magnified. 



8. Dichelaspis Lowci, (magnified nearly ten times.) 

 8a. „ „ fork of carina of, viewed inter- 

 nally. 



