63 



Kellia rostellata, spec nov. Plate xi., fig. 14. 



Shell minute, rather thin, semi-translucent, broadly heart- 

 shaped, a little longer than high, inequilateral and moderately- 

 convex. 



The dorsal margin is oblique on both sides, longer behind than 

 in front, and excavated in front of the beaks. The ventral mar- 

 gin is rounded and curves upwards to the narrow and subros- 

 trated anterior margin. The umbos are prominent, rather obtuse 

 at the apex, approximate, not curved in front, and situated well 

 in advance of the middle line. 



The surface is finely and closely concentrically striated ; the 

 colour is yellowish-horn, umbos and hinge-line brown with a 

 vertical ray of the same colour increasing in breadth from the 

 umbo to the ventral margin. 



Dimensions. — Antero-posterior diameter, about 2-5 ; umbo-ven- 

 tral diameter, 2 ; sectional diameter of united valves, 2 milli- 

 metres. 



Locality. — Dredged in life, seven to nine fathoms, attached to 

 seaweed. Port Phillip Heads, Victoria (J. B. Wilson). 



This species has a general resemblance to Lascf^a rubra ; but 

 apart from the difference of dentition, it is distinguished by its 

 subrostrated anterior side. 



Montacuta semiradiata, spec. nov. Plate xl,, fig. 2. 



Shell minute, transversely ovate, moderately convex ; umbos 

 antemedian, thick and rounded ; anterior and posterior margins 

 rounded, ventral margin slightly curved outwards, posterior slope 

 gently descending. 



Surface smooth, shining, of a chocolate-brown colour, more or 

 less translucent-white medially, with a few distant angular 

 threads, appearing as pellucid rays, radiating from the umbo to 

 the posterior half of the ventral margin. 



Dimensions. — Antero-posterior diameter, 2 ; umbo-ventral 

 diameter, 1-5. 



Locality. — Parasitic on Echinocardium, east of Mud Island, 

 Port Phillip, in seven to ten fathoms (J. B. Wilson). 



Ephippodonta, gen. nov. 



Name in allusion to the cardinal teeth riding as it were one on 

 the other by their tips, and not interlocking. 



:r2/jr?es.^Scintilla lunata, Tate., and Ephippodonta McDougalli, 

 spec. nov. 



Shell like Galeomina, flexible in life but brittle when dry, with 

 two cardinal teeth in each valve, which are more or less bifid at 

 their summits and opposed to each other and not alternating ; a 

 large cartilage is wedged in between the teeth, and the dorsal 

 margin is internally thickened. 



