60 BULLETIN OF THE 



Rep., p. 232, 1821. Cuvier, Regne An., ed. ii., 1830. Swains., Mai., pp. 252, 



301, 1840. Carpenter, Lect, ed. ii., p. 86. Chenu, Man. de Conchyliogie, I. p 



398. Gray, Guide, p. 204. 

 Ombrella, Blainville, Diet. Sci. Nat., XXXII. p. 267, 1824. Mai., p. 174, 1825. 

 Umbella, Orb., Moll. Cub., I. p. 115, 1841. Pal. Franc. Ter. Cret, II., 1842. (Not 



of Griffith and Pidgeon.) 

 Acardo, Menke, Syn. olim, 1828. 

 Operculatum, H. & A. Adams, Gen. Rec. Moll., II. p. 41, 1854. (Linne', Mus. Tess., 



1753, not binomial.) 

 Patella, sp. of the older authors. 

 Not Acardo, Lam., 1801 (= whale's vertebra) ; nor of Commercon, Brugiere, 



Cuvier, Muhlfeldt, or Swainson; (= genera of bivalves.) 



Type, U. umbrella Gmelin, East Indies. 



The name Operculatum, applied by the brothers Adams to this genus, was 

 not used by Linne in a binomial sense, and is barred by the rules of nomen- 

 clature now almost universally adopted. 



The trivial French name applied by Lamarck was first Latinized by Schu- 

 macher in the form Umbraculum, with a proper diagnosis. The French trivial 

 name, which had been many years employed among collectors, never had any 

 scientific standing until Latinized by Schumacher. Subsequently, Lamarck, 

 in 1819, Latinized the word in the form Umbrella, and Blainville in the same 

 year used the form Ombrella, but neither of these has any just claim to super- 

 sede the name proposed by Schumacher, which is the first Latin binomial 

 appellation, accompanied by the requisite diagnosis, which appeared in scientific 

 literature. 



Jmbraculum bermudense (Mokch?). 



Plate XIV. Figs. 9, 10. 



Shell rounded in front, subtruncate behind ; thin, translucent yellowish, 

 with a tint of orange near its apex ; surface polished but irregularly malleated 

 as if from irregularities of station ; apex disproportionately pointed compared 

 with the rest of the shell, erect, dwindling rapidly to a blunted point with a 

 slight posterior tendency ; on the back of this is apparently an obscure scar as 

 of a dehiscent embryonal tip or nucleus ; apex about the beginning of the 

 posterior third ; interior polished, anterior horns of the pedal muscles reaching 

 about the anterior third'united by a delicate arched line marking the attach- 

 ment of the mantle ; Ion. 10.00 ; lat. 8.00 ; alt. 4.00 mm. 



A single dead specimen was obtained by Lieut. -Com. C. D. Sigsbee at 

 Station 62, off Havana, in 80 fms., while in search of Pentacrinus. While, in 

 the absence of the soft parts, its position must remain a little uncertain, yet the 

 correspondence of the shell with the young of Umbraculum mediterraneum is so 

 close that I cannot doubt that this specimen is the young of a species of Um- 

 braculum or Tylodina. Since in this state the specific relations seem indetermi- 



