TUBICINELLA TRACHEALIS. 431 



form so entirely different in general aspect, as Tubicinella, 

 should be forced into it. The main difference between 

 these genera consists in the walls being here not folded, in 

 the simpler radii, and in the general shape of the shell and 

 of the included animal's body ; but there are many other 

 minor points of difference. The most novel character in 

 Tubicinella consists in the shell being lined almost close 

 down to the basis by the opercular membrane. In the 

 opercular membrane thus forming a long tube, and in the 

 general shape of the animal's body, we shall presently see 

 that Tubicinella is closely related to Xenobalanus. In 

 numerous other respects Tubinicella is almost equally allied 

 to the latter genus, to Platylepas, and to Coronula. Finally, 

 several points of structure indicate that Tubicinella may be 

 considered as a Coronula, with the shell much simplified in 

 structure. 



4. Tubicinella trachealis. PI. 17, fig. 3 a — 3 c. 



Lepas trachealis. Shaw. Nat. Miscell. (1789 — 1813), vol. 17 



(1806?) tab. 72G. 

 — trache^formis. Wood. General Conch. (1815), tab. 4, fig. 



1—3. 

 Tubicinella trachealis. J. K Gray. Annals of Philosophy, (new 



series), vol. 10, (1825.) 



— major et minus. Lamarck* Annales du Mus. Nat., 



torn. 1 (1802), Tab. 30, fig. 1—2. 



— balj5Narum. Lamar ck. Animaux sans Vertebres, 



(1818). 



— — Chenu. Illust. Conch. (Plate). 



— — Sowerby. Genera of Recent and Fossil 



Shells (Plate). 



— Lamarckii. Leach. Encyclop. Brit. Suppl., vol. 3 



(1824), PI. 57. 

 Coronula tubicinella. Be Blainville. Diet, des Sciences Nat., 



torn. 32, PI. 117, fig. 5 (1824). 



* It may be observed that I have here broken through the great law of 

 priority ; for it appears to me too grossly incorrect to retain the specific name 

 either of minor or majus in a genus including a single species. Lamarck him- 

 self seems to have been of this opinion, by giving, in 1818, the new specific 

 name of balanarum; but Shaw's name oUrac/iea/is has the clear right to priority, 

 if major or minus be rejected. 



