ANIMAL KINGDOM. 309 



hitherto described, except what is sometimes called the 

 operculum, and at others the teeth of the Balanus. The 

 difference in external appearance of this genus from a 

 Pentelasmis is so great, that, until the organization of each 

 be carefully examined, no one will ever think of referring 

 them to the same class. The singular genera Tubicinella 

 and Coronula afford such examples of a new form, both 

 of them being as dissimilar in external appearance from 

 the animals we have been describing, as it is possible to 

 imagine. 



Having now established the affinity of the Cirripeda to 

 the Branchiopod Crustacea, the next question relates to the 

 means by which we are to leave them. Hitherto indeed 

 they have been placed by all naturalists except Dr. Leach 

 close to the Mollusca; yet their affinity to Teredo, as sus- 

 pected by Cuvier, is universally denied by other naturalists, 

 and would never have been allowed by himself, had he 

 not found it necessary to assign some reason for placing 

 these animals among the Mollusca. His eminent col- 

 league M. Latreille seems on the other hand to be inclined 

 to connect them with Ascidia by means of Dr. Leach's 

 genera Otion and Cineras ; but this is evidently a last re- 

 source, and is carrying the disposition to unite them with 

 the Mollusca to so very fanciful a pitch, that I scarcely 

 think many persons will assent to the justness of the affi- 

 nity, even when backed by that weight of authority which 

 must always be due to the opinion of M. Latreille. The 

 series, which he proposes, leaves Fistulana for the Bra- 

 chiopoda, and proceeds to the Cirripedes, thence to the 

 Tunicata and Radiata, with which last he discovers that 

 the Cirripedes possess an evident affinity. 



The arms indeed of the Brachiopoda, and their flexible 



