KEPOET ON THE LAMELLIBRANCHIATA. 239 



concentric lirse, whicli appear rather sharper lietween the carinse than upon the rest of 

 the surface. The dorsal margins are not very sloping, the front one being slightly 

 arcuate, the posterior nearly rectilinear, and the lower outline is regularly widely curved, 

 but faintly sinuated between the keels. The lunule is indistinct, and consists of a very 

 narrow, linear space, bordered on each side by a very small slender lira. The posterior 

 area, on the contrary, is large, limited by the upper of the lateral keels, near which it 

 is concave, and striated by the very fine termination of the concentric lirse. It is raised, 

 along the central line, on each side of which it exhibits a very slender, elevated, arcuate 

 raised line. The interior is glossy, and the outer margin is marked with a veiy small 

 indistinct denticle, indicating the termination of the lower carina. The teeth are fairly 

 strong and about twelve on each side. 



Length 5 mm. height 3, diameter 2. 



Habitat. — Station 185, east of Cape York, North Australia, in 135 fathoms; coral 

 sand. 



This species must not be confounded with the young of Leda chuva, from which it 

 differs in the straighter posterior dorsal margin, finer sculpture, more raised lower keel, 

 and different dorsal area. 



« 

 Leda ensicxda, Angas. 



Leda ensicula, Angas, Proc. Zool. Soc. Lond., 1877, p. 177, pi. xxvi. fig. 27. 

 Habitat. — Station 161, off the entrance to Port Philip, South Australia, in 33 fathoms; 

 sand. 



The type of this remarkable species, presented to the British Museum ])y Mr. 

 Angas, was dredged off Port Jackson Heads, in 45 fathoms, by Mr. Jolm Brazier of 

 Sydney. Its form is so peculiar, and the description given by Angas so good, that there 

 is little fear of its being confounded with any other species. I may mention that the 

 teeth, which are not referred to by Angas, are elongate, very acute, and numerous, 

 especially on the rostrate side. 



Leda corhuloides, n. sp. (PI. XX. figs. 1-la). 



Testa triangulariter ovata, crassiuscula, pallide flavescens, gequilateralis, antice 

 breviter arcuata, postice acuta, impressionem radiantem hand profundam prope 

 extremitatem exhibens, transversim fortiter lirata, antice liris 2—3 obsoletis radiantibus 

 inter costas ornata. Margo dorsi anticus rectiusculus, obliquus, posticus leviter con- 

 cavus, seque declivis; margo ventris late curvatus, postice ad impressionem breviter 

 sinuatus. Lunula elongata, auguste elliptica, impressa, radiatim tenuiter lirata ; area 

 valde latior, acute ovalis, similiter lirata, porca rotundata circumdata. Linea cardinalis 

 valida, dentibus quindenis utrinque instructa. 



