146 



of European seas, and L.fabula, Reeve, of the Australian and 

 Polynesian seas, with actual specimens of which I have com- 

 pared it ; from L. fabula it differs by its fewer concentric 

 ridges, which are thin and elevated, and by the deeper incur- 

 vature in front of the umbo ; from L. spinifera it differs by its 

 fewer concentric lamellae and more pointed umbones. 



Lucina planatella, Tate. 



References. — Trans. Roy. Soc, Tasmania, for 1884, p. 229; 

 Trans. Ro} r . Soc, S. Aust., for 1885, t. xii., fig. 11. 



Left valve orbicular-ovate, subequilateral, moderately thin, 

 nearly flat. Surface ornamented with regularly disposed con- 

 centric, erect, lamelliform ridges of growth, crossed by equi- 

 distant radial threads, producing on the dorsal half an open 

 reticulated appearance ; towards the front the concentric ridges 

 are coarser, and the radial striae finer or nearly obsolete. 

 Umbo depressed acute ; interior margin of valves smooth. 



Dimensions. — Antero-posterior diameter, 33 ; umbo-ventral 

 diameter, 31 millimetres. 



Locality. — Table Cape (JR. M. Johnston !) 



Loripes simulans, spec. nov. Plate xiv., fig. 19. 



Shell somewhat triangularly orbicular, subequilateral, thin 

 Tather inflated ; umbones produced incurved ; antero-dorsal 

 margin conspicuously concave, post-dorsal margin about as 

 long and sloping ; posterior margin roundly truncated. In 

 young shells the anterior side is somewhat produced. Margin 

 of valves minutely crenulated. Surface ornamented with dis- 

 tant, slightly elevated, concentric lamellae. The left valve has 

 two small diverging cardinal teeth ; the right valve with one 

 cardinal tooth, and in each valve there is a post-lateral tooth ; 

 cartilage groove wholly internal, descending obliquely from 

 behind the cardinal area. 



Dimensions. — Antero-posterior diameter, 6*25 ; umbo-ventral 

 diameter, 6 ; sectional diameter, 4 millimetres. 



Locality. — Oyster banks, Aldinga Cliffs. 



Differs from L. icterica, Reeve, in the well-developed con- 

 centric ridges, and in the absence of radial striae, in which 

 respect it agrees with L. assimilis, Angas. From the latter 

 species, which I have not seen, it seems to differ by its coarser 

 concentric ornament and inflated umbones. 



Cryptodon mactrseformis, spec. nov. Plate xix., fig. 5. 

 Shell minute, very thin, triangularly ovate, inequilateral, 

 moderately convex, semipellucid, white, shining. The sculpture 

 consists of very fine striae of growth. Umbones small, only a 

 very little elevated above the dorsal line, acute, situated sorne- 

 ^vhat in advance of the middle. The posterior side is a little 



