BY C. HEDLKY. 427 



Phacoides rugosus, noiu.muL 

 (Plate xxxvii., fig.l7.) 



Lucina (Codakia) seminula Smith, Chall. Rep. Zool. xiii. 1885, 

 p 180, PI. xiii., f.5,5a:(not L. seminuhun Deshayes, Anim. s. vert, 

 foss. de Paris, i. 1858, p.G73, PL xliv., f.5-8; nor L. seminula 

 -Oould, Proc. Bost. Soc. Nat. Hist. viii. 1861, p.36). 



Dr. W. H. Dall, in whose official custody lies the type of L. 

 seminula Gould, states* that it is the same as L. ^nsum Reeve. 

 Further, the name itself is preoccupied. It follows that the shell 

 described and figured in the Voyage of the " Cliallenger " requires 

 a name, which is here supplied. The height of the individual 

 figured is 2-2; length 2-35, and depth of single valve l'05mm. 

 Specimens east of Torres Straits seem less densely concentrically 

 ribbed than those from the west. I have taken it with the pre- 

 ceding species in Van Diemen's Inlet, in 15 fathoms, off the 

 Palm Islands, and at Barney Point, Port Curtis. The species is 

 -abundant off the Hope Islands. 



Phacoides sperabilis, n.sp. 

 {Plate xxxvii., fig.l8.) 



Shell small, solid, inequilateral, rather inflated and oblique. 

 Colour white. Sculpture : the radials aie broad and low, about 

 fourteen in number; sometimes, as in the shell drawn, they run 

 their course unchanged to the margin, in other individuals the 

 ribs multiply by fission or intercalation. The concentric sculp- 

 ture consists of thin, narrow but erect lamellae, which overrun 

 both ribs and interstices, usually faint medially but rising into 

 prominence at the sides. Sometimes they are crowded, and 

 sometimes spaced, and may vary in number from fourteen to 

 over twenty. Inner margin of valve finely denticulate. Height 

 3*15; length 3-25; depth of single valve 1*25 mm. 



The variability of both radial and concentric sculpture changes 

 the appearance of this species. The concentric sculpture is, 



• Dall, Proc. U.S. Nat. Museum, xxiii., 1901, p.81(). 



