276 BULLETIN OF THE 



Habitat. Off Bahia Honda, Cuba, at Station 19, in 310 fms., one specimen. 



The other recent species most like this is the S. borealis of Verrill, in which 

 the sculpture of the umbilical margin is -wholly dissimilar, and quite faint in 

 comparison. 



Genus OMALAXIS Deshates. 



Omalaxis Deshayes, Encyc. Me'th., Tabl., 1830. (Solarium bifrons Lamarck.) 



Omaloxon (Desh. em. !) Agassiz, Nomenclator Zobl., 1846. 



Omalaxon (Agassiz em.) Herrmannsen, Ind. Gen., II. n. l /l 4. 



Omalalaxis (Desh.?) Herrmannsen, loc. cit., p. 144. 



Bifrontia Deshayes, Encyc. Me'th. TTI. D . 659, 1832. Lam., Hist. An. s. Vert., IX. 



p. 103. 

 Orbis Lea, Contr. to Geol., p. 123, 1833. (0. rotella, pi. iv. fig. 112.) 

 Discohelix Dunker, Pal., p. 132, 1849; Handb. Conch., p. 500. 

 Homalaxis (Desh. em.), Fischer, Manual, p. 715, 1885. 

 Homolaxon (as of Agassiz) Watson, Chall. Rep. Gastr., p. 137. 

 Not Omalaxis Tryon, Syst. Conch., II. p. 219 (?= Adeorbis). 



The above partial list of synonymy gives a pretty fair idea of what happens 

 when authors take it upon themselves to modify generic names in the supposed 

 interest of grammatical accuracy. Unless there is a palpable typographical 

 error, or the form of the word is essentially incompatible (apart from its mean- 

 ing) with a Latiniform nomenclature, there is no sufficient reason for reforming 

 it. It is of no consequence whatever, that Omalaxis is erroneously constructed. 

 It is of serious consequence that the nomenclature of biology should not be 

 burdened with eight or ten unnecessary synonyms. 



Omalaxis is divided by Dr. Fischer. 0. zanclea Philippi, which has a 

 Torinia-like operculum, is placed under Torinia with the name of Pseudo- 

 malaxis (possibly identical with Ilaira H. & A. Adams), while the original 

 name is kept for those having a simple thin operculum of many whorls. To 

 the latter group belongs the following species. 



Omalaxis nobilis Verrill. 



Omalaxis nobilis Verrill, Third Cat. Moll., Trans. Conn. Acad., VI. p. 423, pi. xliv. 

 fig. 12, 1885. 



Habitat. Off Chesapeake Bay, v errill, in 70 fms. Off Cuba, near Morro 

 Light, in 119-292 fms., Sigsbee; off Sand Key, in 128 fms.; at. Barbados, in 

 103 fms.; and at Station 45, in 101 fms., Lat. 25° 33' N., Lon. 84° 21' W., 

 bottom temperature about 62°.0 F. 



This species should be compared with Bifrontia rochettina Michelotti of the 

 Italian Tertiaries, and with B. (Orbis) Pingdii Morch (Forst Tert. i Dan., 

 p. 24, 1874) from the older sands of Copenhagen, but I have not the specimens 

 accessible for this purpose. The nucleus in 0. nobilis is sinistral, as in other 

 members of the family, though some care is necessary to observe this, the plane 

 of the shell being verv uniform. 



