TUGONIA.— Plate I. 



(liately ridged throughout, ridges in-egular, latticed 

 and finely crenulated with concentric striiP, anterior 

 side very large, posterior very short, broadly beaked. 

 Hall. West Africa. 



Tlic shell is in this species comparatively rather com- 

 |)ressed, while the radiating ridges are stronger, crenulated 

 on the summit, finely latticed in the interstices. 



Species 4. (Fig. 4 a, Mus. Cuming.) 



Ti'GONiA SEMisuLCATA. Tug. testct oblique glohosd, glb- 

 bosd, alba, radiatim temdliratd, liris striis concentricis 

 ridmde dense clathratis, area antlcd sine liris radian- 

 iibns, latere postico modice rosiralo. 



The half-gkooved Tugonia. Shell obliquely globose, 

 gibbous, white, radiately finely ridged, ridges mi- 

 nutely closely latticed with concentric striae, anterior 

 area without radiating striae, posterior side mode- 

 rately beaked. 



Adams, Gen. Rec. MoU. vol. ii. p. 35.5. 



Hab. West Africa. 



Tlie anterior area of this and the following species is 

 sculptured with concentric ridges, bat the radiating ridges 

 are wanting. They cease at the side, in a line sloping 

 from the umbo. The grooved contraction of the specimen 

 here represented, as seen in the upper part of the figm-e, 

 is merely an accident of growth. 



Species 5. (Mus. Cuming.) 



Tugonia xobilis. Tug. testa globoso-oblongd, antice 

 gibbosd, alba, radiatim tenuiUratd, liris dense clathra- 

 tis ad later a obsoletis, latere antico obtuse angulato, 

 postico truncato-rostrato. 



The noble Tugonia. Shell globosely oblong, ante- 

 riorly gibbous, white, radiately finely ridged, ridges 

 closely latticed, obsolete at the sides, anterior side 

 obtusely angled, posterior truncately beaked. 



Abams, Gen. Rec. Moll. vol. ii. p. 355. 



Hab. West Africa. 



This species scai-cely dift'ers from T. anatina, except in 



being of a more oblong form. 



Species 6. (Pig. 4 b, Mus. Cuming.) 



Tugonia siphonata. Tug. testa oblique globosd, albd, 

 undique radiatim Virata, liris confertis, irregularibus, 

 minute crenulatis, latere antico gibboso, peramplo, pos- 

 tico subproducto, expanso-rostrato. 

 The spouted Tugonia. Shell obliquely globose, white, 

 everywhere radiately ridged, ridges close, iiTegular, 

 minutely crenulated, anterior side gibbous, very large, 

 posterior rather produced, pointedly beaked. 

 Hab. West Africa. 



It wOl be observed by the numbering of this species 

 that it was taken originally to be a variety of T. semisul- 

 cata, but the radiating ridges, as in T. compressa, range 

 throughout ; they do not stop short of the anterior area. 



