36 PROCEEDINGS OF THE NATIONAL MUSEUM vol.66 



Genus MARGIN ELLA Lamarck 



MARGINELLA (FABA) BULLBROOKI, new species 



Plate 5, fig. 1 



Shell small, solid, stout, semibiconic, highly polished, prominently 

 axially sculptured, and three and one-half whorled. Spire less than 

 one-fourth length of shell, broadly conic ; last whorl gradually slop- 

 ing from the peripheral shoulder to the broad base. Apical whorl 

 smooth, bluntly rounded and partly concealed by callus. Suture of 

 following Avhorls appressed and overlapping the preceding whorl 

 nearly to the periphery; suture bordered below by a faint spirally- 

 sculptured, wide, raised, slightly anteriorly-depressed, nearly fiat 

 plication, below which the shoulder steeply ascends. Axial sculpture 

 of about twelve strong, rather sharp, triangular ribs, extending from 

 the base of the shoulder behind to the suture on the spire whorls and 

 forward on the body whorl nearly to the anterior extremity. Aper- 

 ture moderately narrow, linear, shallowly channeled posteriorly, 

 rounded and slightly expanded at the canal ; outer lip with a promi- 

 nent varix, inner margin ornamented with about nine denticles — 

 denticles reduced at either extremity ; pillar provided with four 

 blunt-edged plications, the posterior two nearly transverse, anterior 

 two oblique and the anterior one marginates the canal and joins the 

 lip-varix. 



Dimensions: Type (U. S. Nat. Mus. Cat. No. 352648) measures: 

 Length 4.3 mm. ; greater diameter 2.7 mm. ; length of aperture, 

 3.4 mm. 



The new species is imique. In a general way it is similar to a 

 recent species Marginella faba Linnaeus from Senegambia, west 

 coast of Africa. This very interesting species is named in honor of 

 the collector, J. A. Bullbrook. 



Occurrence. — Middle or lower Miocene: In flood-wash, 1 mile south 

 of Brasso. 



MARGINELLA (FABA) BRASSOENSIS, new species 



Plate 6, fig. 4 



Shell small, polished, prominently axially sculptured, four 

 whorled. Spire high, about one-third length of shell, whorls moder- 

 ately inflated ; body whorl inflated, roundly shouldered in front of the 

 suture and evenly sloping to the base. Apical whorl smooth, short and 

 bluntly rounded ; following whorls with a low subsutitral spiral line 

 marginating the appressed suture, below which is the whorl constric- 

 tion. Spire and body whorl axially sculptured by about thirteen 

 sharp, vertical ribs, separated by rounded intersj^aces and extending 



