Resania.] PELECYPODA. 973 



Genus 2. EESANIA, Gray, 1852. 



Resania, Gray, A.M.N.H. (2), x, 1852, 43. Type: R. lanceolate, Gray. 

 ResiiHin, Dall, Trans. Wagn. Free Inst., iii, pt. 4, 889. Vanganella, Gray, 

 1853. Myomactra, C. Mayer, 1867. Laminaria, ('. Mayer, 1867. 



Shell inequilateral, thin, compressed, lanceolate, smooth, with a 

 conspicuous epidermis ; dorsal areas obscure ; beaks very low, ad- 

 jacent, somewhat posterior ; pallia! sinus short, broad, gapes con- 

 spicuous ; ligament small, short, lanceolate, not set off from the pit 

 by a shelly ridge ; chondrophore large, oblique, posteriorly depressed 

 below the hinge-plate and resting on a radial thickened rib, which 

 extends from the beaks towards the base behind the posterior ad- 

 ductor ; a second rib of the same sort reinforces the valve behind the 

 anterior adductor ; resilium homogeneous, dental armature concen- 

 trated ; left cardinal strong, prominent, petaloid, with a thin posterior 

 accessory lamella, which, with posterior arm of the tooth, projects 

 slightly over the pit ; a short, thin, well-elevated lateral tooth on 

 each side of the beak ; a small but deep luuular inflection of the 

 anterior dorsal margin ; right cardinal low, wide, the anterior arm 

 superposed on the ventral lamina ; the anterior dorsal lamina very 

 small between the arm of the cardinal and the lunular inflection ; 

 posterior arm of the cardinal projecting a little over the pit ; the 

 posterior laminae small but distinct. (Dall.) 



Distribution. New Zealand ; a single species. 



1. Resania lanceolata, Gray, 1852. Plate 60, figs. 7, a, 



Resania lanceolata, Gray, A.M.N.H. (2), x, 1852, 43. Lutraria (Vanganella) 

 lanceolata, Gray, Crit. List, 43 ; Conch. Icon., viii, f. 17 ; Index, 90. 

 Vanganella Taylori, Gray, P.Z.S., 1851 (1853), 125 ; C.M.M., 65 ; Ereb. & 

 Ter., 5, pi. 2, f. 5 ; Hutton, J. cle Conch., xxvi, 46 ; M.N.Z.M., 140 ; 

 P.L.S. N.S.W., ix, 518 ; Ad. G.R.M., ii, 385, pi. 102, f. 2. 



Shell moderately large, lanceolate, inequilateral, rather com- 

 pressed, white with a yellowish epidermis, concentrically striated. 

 Beaks small, inconspicuous, incurved. Anterior end somewhat longer 

 than the posterior, slightly rostrate, narrowly rounded, the dorsal 

 margin lightly convex, slowly descending ; posterior end with the 

 valves gaping, broadly rounded, a faint ray passing from the unibo 

 to the middle of the posterior margin on each valve ; basal margin 

 very little curved. Sculpture consisting of fine unequal concentric 

 striae, with wrinkles of the epidermis on the upper hinder slope. 

 Epidermis thin, yellowish-brown, usually worn off on the upper part 

 of the valves. Colour white where the epidermis is lost, light 

 yellowish-brown on the vertical part, darker brown on the upper 

 part of the front edge. Interior with 2 strong radial ribs, white, 

 lightly iridescent in some places. Margins smooth, thin and sharp. 

 Hinge normal, as described for the genus. Ligament very short, 

 behind the beaks. Adductor-scars large, not deep, the anterior pyri- 

 form, the posterior oval. Pallial sinus high and short, straight in 

 front, ending at the posterior radial rib. 



Length, 100 mm. ; height, 49 mm. ; diameter, 18 mm. 



