EXPLANATION OF THE PLATES. 379 



Kg. 



9. Dichelasjris Grai/ii, (magnified eight or nine times.) 



10. Dichelaspis orthogonia, (magnified six times.) 

 10#. „ „ carina, lateral view of. 



103. „ „ basal end of carina, viewed 



internally, much magnified. 



TAB. III. 



1. OxgnasjAs celata, (magnified three times.) 



la. „ „ with the skin of the encrusting 



horny zoophyte removed, (a), 

 scutum; \b), tergum; and {c), 

 carina. 



2. Conchoderma virgata, (magnified twice.) 



2a. ,, „ carina, viewed externally. 



25. „ „ summit of capitulum, showing 



the terga from vertically 



above. 

 2c. „ ,, var. chelonophila, (magnified 



four times). 

 2d. „ „ var. Olfersii, (scutum.) 



3. Conchoderma Hunteri, (magnified five times.) 



4. Conchoderma aurita, (nat. size,) with the rudimentary 



carina exhibited on the right 

 hand. 



4a. „ „ summit of capitulum, viewed 



from vertically above, show- 

 ing the ear-like appendages 

 and rudimentary terga. 



43. „ „ section near the bases of the 



ear-like appendages, showing 

 their folds. 



4c. „ „ (var.), scutum. 



5. Alepas minuta, (magnified five times.) 



6. Alepas cornuta, (magnified five times.) 



