^°1893^''] PROCEEDINGS OF THE NATIONAL MUSEUM. 337 



Three speeiineus; Cai)e Town (Miis. >«o. 1253SU) a pretty well-marked 

 species. 



Family TKOCHID^:. 



Geuus MONODONTA Lamarck. 



Section OSILINUS Philippi. 



109. Osilinus Tamsi Danker 



?=0. ,S'«»/cv/j W. & B. 

 ?+J^- puurtnhita Lamarck. 



Commou liviiij;-; Porto Grande (Mus. No. 125580). 



Variable in umbilicial character and otherwise: sometimes elevated, 

 conical, and again frequently depressed j ofteu exhibiting- two or three 

 obtusely rounded ribs following the periphery spirally, with a shallow 

 groove between. Some examples are (^loselj^ spirally lirate, and others 

 are without lira*. Specimens are frequently met with that are ob- 

 tusely angulated. Some individuals are ornamented with light zigzag 

 markings, others have only a fi^w distant light spots on a dark ground; 

 these i)oint intimately towitrd punetulata. Apex when eroded, yel- 

 lowish. 



Section OXYSTELE Philippi. 



110. Oxystele sagittifera Lamarck. 



Three living specimens; Cape Towu (Mus. No. 125373.) 



Geun« GIBBULA Kisso. 



111. Gibbula nassaviensis Chemnitz. 



Iz^Gibhula umhillcaUi^ Montagu, variety. 



Three specimens; Porto Grande (Mus. No. 125359). 



The three shells of the foregoing sitecies, collected as above, are in 

 good condition. In the National collection under the same name I tind 

 numerous exiimples that were identitied by the late Br. Stimpson (Mus. 

 No. 18G80). Upon tui-ning to the author I find his description alto- 

 gether too brief, and tlie figures too indefinite to make a satisfactory 

 determination thereby. Neither upon following his name through the 

 synonymy is a satisfactory result obtainable as to the identity of the 

 shell he has named. The umbilical (character is of no value whatever 

 in this instance, for some individuals are distinctly umbilicated, others 

 are not, and again others are ])artially perforated. The shells, con- 

 sidered ai)art from the confusion of names and conjectures as to the 

 meaning of authors, appear to be an extra limital and dwarfed aspect of 

 umhilicaris Linne = T. umhUicatus Montagu. 



Philippi makes naHHaviensis a synonym of his occulta; and A. Adams 

 includes nassaviensis preceded by a ? in the synonymy of Gihbula 

 Proc. N. M. 93 22 



