LITHOTRYA. 



the general resemblance which the animals bear to each 

 other, and the analogy which exists between the shelly 

 valves of the various species. Bruguiere has also done 

 well in separating the pedunculated from the sessile 

 Cirripedes, under the Generic name Anatifa; but we are 

 indebted to Dr. Leach for a more complete elucidation of 

 the class, and a systematic division of it into orders and 

 Genera, most of which being formed from a consideration 

 of the peculiarities in character and habits, are natural and 

 well characterized. Lamarck has followed Bruguiere in 

 his " Systeme," but in his Hist. Nat. des Anim. sans vert, 

 he has rather follov/ed Leach, omitting some of his Genera, 

 so that upon the whole we may consider the arrangement 

 of this class as well established, and we gladly acknow- 

 ledge the obligations we are under to all the above-men- 

 tioned writers, and cannot withhold from them the tribute 

 of our praise, which they so justly merit ; but at the same 

 time, we must mark our disapprobation of the arrangement 

 of a later writer, who has dissevered " from this 



Class, and placed Chiton and Chifonellus, between it and 

 Anatifa because it has only two testaceous valves, thereby 

 doing a sort of violence to nature, in order to harmo- 

 nize his system, and arrange all bivalves together. 



The Genus we are now about to describe belongs to 

 the pedunculated Cirripedes, and it might with great pro- 

 priety be placed at the beginning of that order, because 

 it has several peculiarities in common with the sessile 

 Genera, particularly the shelly base, and, considering some 

 of the valves as ajialogous to what is by common consent 

 called the operculum of the Balani, we must, nevertheless, 

 regard the dorsal valve, the small lateral inferior valves, 

 and the still smaller anterior valve, in this Genus particu- 

 larly, as analogous to those valves in Balanus that are 

 united together in the form of a cone, and form the ex- 

 ternal covering of the animal, but which are here raised 

 upon the peduncle, and partly surround the base of the 

 operculum. 



Shell, of a somewhat irregular pyramidal form, with 

 compressed sides, fixed upon a tubular, tendinous peduncle, 

 and surrounded by a few rows of very small scales at the 

 top of the peduncle, which is covered all over by a great 

 number of still smaller scales. Valves eight, contiguous, 

 unequal in size; the two anterior pairs which surround 

 the opening for the passage of the ciliated tentaeula of the 



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