140 AMERICAN JOURNAL 



figure, which gives a very erroneous idea of the hinge line. 

 Chenu's figure is better, but the cardinal process is too prominent, 

 and the area below the hinge line quite incorrect. The cardinal 

 process is hardly perceptible at all, the septum is prominent and 

 grooved on the upper edge. The apophysary processes are broad 

 and folded together, having a sulcate or bifid appearance ; the 

 interior edges are approximated and the exterior edges are some- 

 what produced into a rounded point. On opening a dried speci- 

 men I could detect no central spiral lobe ; this may have been 

 owing to the condition of the individual. The interior of the 

 shell is prettily marked with eight or ten radiating rows of tu- 

 bercles on each side, and is very conspicuously punctate. The 

 transverse ridge or septum, in the apex of the neural valve, is 

 well marked in my specimens. The neural valve is emarginate 

 anteriorly, and the margin of both valves is consequently some- 

 what flexuous. The pedicel muscular scars are minute, but 

 perceptible. The other species of this genus are : 



Kraussina cognata, Chemn., Dav. An. Nat. Hist. 1852, p. 



370. 

 Mab. South Africa. 



Kraussina pisum, Lam., (Val.) Hist. Nat. An. s. Vert. 2d ed. 



vii, p. 330,= Terehratula natalensis, Krauss. 

 Ilab. South Africa. 



Kraussina capensis. Ad. and Rve., Zool. Samarang, p. 71, pi. 



21, fig. 4. = Kraussia Deshayesii, i)av. 

 Hah. Cape of Good Hope. 



This species was named eapensis by Ad. and Rve. The name 

 was admissible, as Gmelin's capensis is a synonym of rubra, 

 Pallas. It was afterward described by Mr. Davidson as K. 

 Deshayesii, which name, for the above reasons, must stand as 

 a synonym. The species is, very probably, identical with Kraus- 

 sina rubra, and I doubt if Kraussina pisum and K. cognata are 

 not also different ages of one species. The denticulated margin 

 mentioned by Reeve as peculiar to cognata is probably an indi- 

 vidual peculiarity, and similar to the marginal tubercles in old 

 and thickened specimens of Megerlia truncata. 



? Kraussina picta, Val., Verh, Zool. Bot. Ges. Wien, 1865, 



p. 894. 

 Kab. St. Paul Island, Indian Ocean. 



Genus BOUCHARDIA, Dav. 

 Terehratula, Blainv., Diet. Sci. Nat. liii, p. 145, 1828. 



