CORONULA* 



Stance, in those species which are found attached to 

 cetaceous animals, divided into radiating cells: in such 

 as are found upon the Turtle, more solid and divided 

 only at the base into irregular dentated ramifications. 



Lamarck tells us that the shells of this Genus are 

 not only found upon cetaceous animals and Tortoises, hut 

 also upon hard substances, such as shells, &c., but we 

 have never met with them. The species that are found 

 upon the whale in the southern ocean, such as C. Diadema, 

 and BalcBnaris are partly imbedded in the skin and fat of 

 the whale, which fills the radiating cells in the substance 

 of the shells; consequently this Genus does not appear to 

 us to be closed beneath at all, not even by a membrane 

 as Tubicinella is. 



The few species of this Genus with which we are 

 acquainted, with the exception of C. testudinaria, have six 

 sets of longitudinal ribs, small, few, and converging at 

 the upper end, but increasing in breadth and number 

 towards the lower extremity, and their interstices are 

 smooth and finely striated; but in the C. testudinaria the 

 valves are themselves smooth, and their interstices di- 

 vided into small cells. We consider it incumbent on us 

 to mention a very singular specimen which we have seen 

 in Mrs. Mawe's private collection, whose outer shell 

 consists of only five pieces; this can, however, only be 

 considered as an accidental variation. 



We acknowledge with much thankfulness the per- 

 mis^on that has been afforded us by the Curators of the 

 museum of the Royal College of Surgeons, to examine 

 and draw one of the very fine specimens of Coronula 

 piadema, which are preserved in that collection. 



