32 PROCEEDINGS OF THE ACADEMY OF [Jan., 



umbilicus, on the side opposite the aperture. The margin of the 

 umbiHcus is more or less distinctly crenulate. 



Alt. 5.5, diam. 6 mm. 



Tanabe, Kii. Types No. 85,992, A. N. S. P., from No. 1,457 of Mr. 

 Hirase's collection. Also from Tokyo Bay. 



In some of the specimens, especially those not ciuite mature, there is 

 some white mottling in the peripheral region, and a white area around 

 the umbilicus. The specimens from Tokyo Bay w^hich I provisionally 

 refer to this species want the subsutural and umbilical plication. 



PHASIANELLID^. 

 Phasianella tristis Pils. PI. VI, fig. 64. 



Nautilus, XVII, 69 (October, 1903). 



Rishiri, Kit ami. 



TROOHID^. 

 Trochus Mrasei n. sp. PI. V, figs. 52, 52a. 



Shell imperforate, pyramidal, with the outlines slightly convex below 

 and noticeably concave along the upper half of the spire; base flat. 

 White, with bold radial stripes of blood-red or purplish-red on the later 

 whorls, the spire ver}' minutely and copiously speckled with olive-green 

 and red, the latter color predominating on the spiral cords. Base 

 whitish, tessellated with blood-red ol^long spots on the spiral cords. 

 The upper half of the spire is sculptured with short obliquely vertical 

 waves on the lower third of each whorl, terminating in nodes above 

 the suture; above these waves there are several low, weakly granose 

 spiral cords. The waves gradually diminish on the penultimate 

 whorl and are nearly obsolete on the last, and the spiral cords increase 

 in number and strength. The periphery is acutely angular in front 

 but in fully adult shells becomes blunt behind the lip. The fiat 

 base is sculptured with about 12 ver}^ low and smoothish circular cords. 

 The aperture is smooth and silvery within. The columella bears an 

 acute lobe above, separated from the iDase b}^ a deep incision, and it 

 terminates below in an oblong, whitish tubercle. The umbilical 

 region is pearly as usual. 



Alt. 50, diam. 45 mm. 



Tanal^e, Kii. Types No. 82,104, A. N. S. P., from No. 1,295 of Mr. 

 Hirase's collection. 



Trochus Mrasei differs from T. conus Qm.}'^ in its wider base, acutely 



'^ The synonymy of this species, which is commonly known by the non-binomial 



name given by Chemnitz, is as follows: 



Trochus conus Gmel., Syst. Nat. (13), p. 3,569 (1790), based upon 



Trochus acutangulus, etc., Chemnitz, Conchyl. Cab., V, p. 81, PI. 167, fig}. 1,610 



(1781). 



