On Some Neiv Species of Marine Mollusca. 65 



The ventral margin is rounded and curves upwards to the 

 narrow and subrostrated 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 2d milli- 

 metres ; umbo-ventral diameter 2 millimeti-es ; sectional 

 diameter of united valves 2 millimetres. 



Locality. — Dredged in life 7 to 9 fathoms, attached to 

 seaweed, Port Phillip Heads, Victoria. J. Bracebridge 

 Wilson. 



This species has a general resemblance to Lascea rubra, 

 but, apart from the difference of dentition, it is distinguished 

 by its subrostrated anterior side. 



Montacuta semiradiata spec. nov. — 



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 millimetres ; 

 umbo-ventral diameter lo millimetres. 



Locality. — Parasitic on Echinocardium, East of Mud 

 Island, Port Phillip, in 7 to 10 fathoms. J. Bracebridge 

 Wilson. 



. Stylifer brunneus spec. nov. — 



Shell sub-globose ; spire short, acuminately produced ; 

 apex cylindrical, styliform ; the other whorls are convex, of 

 moderate increase, slightly depressed at the posterior suture ; 

 sutures linear. Last whorl large, faintly angulated at the 

 base, and depressed at the sutu)'e ; and in consequence, having 

 a perceptibly sub-quadrate outline. Outer lip thin, regularly 

 curved, acutely angled posteriorly ; columella thin, slightly 

 elevated, defined by a superficial groove behind. Colour 



F 



