REPORT ON THE LAMELLIBRANCHTATA. 99 



(lorsalcm ambiens. Umbones parvi, acuti, subprominentcs. Cardo normalis, dente postico 

 valvsc (lextrse, antico in sinistra triangulari bifido, lateralibus fere ijjquidistantibus. 



This shell is transversely elongated, sharply rounded in front, narrowed and some- 

 what rostrate at the opposite end. It is slightly inequilateral, the anterior side being a 

 little the longer. It is thin, semipellucid, whitish or tinted with pale yellow at the 

 upper part, and ornamented with fine concentric lirse which are more numerous upon the 

 anterior half of the valves than behind. Besides these there are others more closely 

 packed and scarcely visible to the naked eye which radiate from the small acute 

 prominent umbones and produce upon the concentric ones a somewhat crenulate appear- 

 ance. The dorsal margin is about ecj^ually sloping on both sides, straight or the slightest 

 convex anteriorly, and feebly concave at first Ijehind the umbones. The lower outline 

 is broadly arcuate at the middle and in front, but slightly incurved posteriorly. The 

 dentition of the hinge is the same as in the typical section of the genus, and the paUial 

 sinus is deep and rounded at the end. 



Length 8 mm., height 4 J, diameter 2. 



Habitat. — Station 185b, off" Cape York, North Australia, in 155 fathoms; coral 

 sand. 



The specimens here described are possibly young shells, but the peculiarity of the 

 sculpture will readily distinguish the species. 



Tellina compacta, n. sp. (PL III. figs. 9-9e). 



Testa elongata, subdonaciformis, valde inaequilateralis, antice rotundata, postice 

 angustata, subcuueiformis, mediocriter convexa, alba, interdum dilutissime rosea, zonis 

 angustis paucis peUucidis ornata, incrementi lineis fortiter striata. Margo dorsi anticus 

 perelongatus, parum declivis, subrectihnearis, posticus valde obliquus, rectus, brevis. 

 Margo ventris leviter arcuatus, anterius rotundatim, posterius parum adsceudens. 

 Umljones parvi, acuti, circiter in \ longitudinis collocati. Dentes cardinales duo 

 lateralisque unicus in utracpie valva ; ligamentum breve, flavo-fuscum, prominens. Pagina 

 interna nitens, paulo iridescens, pallii sinu magno profundo notata. 



The form of this species recalls that of certain varieties of the genus Donax. It is 

 not quite twice as long as high, rounded and only slightly narrowing antei-iorly, much 

 shorter behind, narrowed and somewhat wedge-shaped. It is very inequilateral, the 

 anterior side constituting by far the larger portion of the shell. It is moderately strong 

 and thick, a little convex, slightly gaping at both ends, whitish, or witli a l)]nsh of pink, 

 varied at intervals with narrow bluish somewhat pellucid zones, and sculptured with fine 

 concentric lines of growth, which, howcA'er, are rather coarser near the ventral edge. 

 The front dorsal margin is almost twice as long as the posterior, almost horizontal and 



