Zoological Society. 4G5 



hand integro ; tared cardinali angustd, deltidiis purvis, trigonali- 

 bus ; valvd ventrali planulatd, margine postico rectiusculo ; sulco 

 mediano subperspicuo ; ossiculo interno ramulos duos centrales, 

 divergentes, ad apices expansos sistente ; margine interno valvarum 

 denticulato. 

 Shell nearly trapezoidal, rounded in front, of a pale colour, some- 

 times reddish ; valves unequal, obsoletely radiately striated, the striae 

 entirely obliterated near the margin ; marginal line flexuous in front 

 and on the sides ; dorsal valve convex, with an inconspicuous central 

 ridge, its apex somewhat acuminated, reflected, with a large incom- 

 plete perforation ; cardinal area narrow, with small triangular del- 

 tidia ; ventral valve flattened, its posterior margin nearly straight, 

 with a scarcely evident central furrow ; internal appendages con- 

 sisting of two little central diverging branches, expanded at their 

 apices ; margin of the valves denticulated within. 



There are two varieties in colour, from South Africa, according to 

 the late G. Humphrey. 



Terebratula transversa. Ter. testa transversim subovatd, tenui, 



rudi, glabrd, pallescente ; lined marginali subflexuosd, antice sub- 



sinuatd; for amine maximo, incompleto ; ared cardinali magnd, 



planatd ; deltidiis parvis, longe discretis ; carind dorsali incon- 



spicud, rotundatd; valvd ventrali transversim oblongd, antice 



rotundatd, postice in angulo obtusissimo desinente ; sulco mediano 



subinconspicuo, rotundato ; margine valvarum integro. 



Shell transversely subovate, thin, rugose, smooth, of a pale colour ; 



marginal line somewhat flexuous, slightly sinuated in front ; dorsal 



valve of a somewhat tetragonal ovate form, very obtusely angular 



behind and reflected ; perforation very large, incomplete ; cardinal 



area large and flattened ; deltidia small, very distant ; mesial ridge 



rounded, indistinct ; ventral valve transversely oblong, rounded in 



front, and finishing in a very obtuse angle behind ; mesial groove 



rounded ; indistinct margin of the valves entire. 



In Mr. Norris's collection and in that of Mr. Janelle. 



Terebratula rubella, Sow. Ter. testd subovatd, postice sub- 

 acuminatd, subgibbd, antice subsinuatd, rubrd ; valvis incequalibus, 

 glabris ; lined marginali rectiusculd, antice subsinuatd; valvd 

 dorsali postice subacuminatd, reflexd, carind mediand nulla, sulco 

 mediano obsoletissimo , for amine parvo ; ared cardinali angustd, ad 

 later a rotundatd, deltidiis majusculis, coalescentibus ; valvd ven- 

 trali ovatd, sulco mediano latiusculo, emarginationem anticam 

 efformante ; ossiculo interno ut in T. australi ; margine valvarum 

 Icevissimo. 

 Shell nearly oval, rather acuminated posteriorly, a little gibbous 

 and slightly sinuated anteriorly ; valves unequal, smooth ; marginal 

 line nearly straight, a little sinuated in front ; dorsal valve rather 

 acuminated posteriorly, reflected, without any mesial ridge, but with 

 a very obsolete mesial furrow ; perforation small ; cardinal area 

 narrow, rounded at the sides, with rather large united deltidia ; ven- 

 Ann. ty Mag. N. Hist. Vol. xviii. SuppL 2 L 



