Plate XV. 



-Campylodiscus dt Tonianus, Deby 

 C. sttUatits, Grev. var., Deby. 

 -C. undulatuS) Grev., var. Deby. 

 ■C. Hardmanianus^ Grev. 

 ( '. KerguelensiS) Deby. 



\I tssrs. Berthaud Freres, of P.iris, deserve credit for the 



manner in which they have executed all of the phototypic plates 

 for the present paper; and Mr. C. Seers, of Bath, tor its careful 

 typography. 



