22 PROCEEDINGS OF THE ACADEMY OF [1896. 



as usual, the siphon nearly straight, a little recurved. Aperture 

 livid brown within, contained 1"8 times in length of shell ; outer lip 

 regularly arched, multilirate within, the lirse extending to within 

 about I2 mm. of lip-edge; columella concave above, straight, verti- 

 cal and more heavily calloused in the middle, slanting to the left 

 below. Alt. 47, diam. 24 mm. 



Yokohama, Japan. 



Allied to S. ficsoides, fiiscolineata, etc., but in this species the ver- 

 tical waves of the shoulder are entirely absent on the spii e ; the 

 canal is nearly straight. 



In this connection it may be well to call attention to the fact, 

 kindly communicated to me by Mr. J. Cosmo Melvill, that Siphon- 

 alia Stearnsii Pilsbry is identical with S. psexidohuccinum Melv. and 

 S. hyperodon Pils. is the same as IS. Mikado Melv. Mr. Melvill's 

 names were proposed in the Journal of Conchology (Leeds), V, p. 348, 



Ischnochiton aspidaulax n. sp. 



Shell oblong, slightly narrower in front, moderately elevated, 

 carinated, the side slopes nearly straight. Surface somewhat shin- 

 ing, and (a) dark olive at the sides, a light olive band dappled with 

 darker spots along the ridge, or (6) light dull bluish dappled with 

 brown, and with some snow-white patches on valves ii, iii, v and vi ; 

 yellowish at the apices of valves. 



Median valves not beaked, the sutures concave. Lateral areas 

 well defined, but only a trifle raised, sculptured with numerous dis- 

 tinct, unequal radial grooves, not extending to the apex, and parted by 

 unequal spaces, densely sculptured with oblique or Y-shaped scale- 

 like granules, the apices of the V's directed toward the beaks. Central 

 areas very densely and minutely sculptured with longitudinal irreg- 

 ular wrinkles, somewhat converging, becoming finer toward the 

 ridge, coarser in front of the diagonal line. Posterior valve with 

 the mucro slightly projecting, somewhat in front of the middle, pos- 

 terior slope somewhat concave. 



Interior bluish, with olive stains behind the valve-callus. Sinus 

 rather i\arrow, straight and smooth, angular at the sides. Valve i 

 with 10, valves ii to vii with 1-1, valve viii with 10 slits. Teeth 

 rather long, sharp and smooth. Eaves narrow, deeply grooved 

 above the teeth. 



Girdle covered with compactly, irregularly imbricated glossy 

 scales, very weakly striated, and measuring "8 to '25 mm. in width ; 

 each scale olive-blackish with a broad outer border of white. In a 



