238 K. MITSUKURI : STUDIES ON 



middorsal intorradialia is like tlic lateral dorsal radialia. There 

 are five small teeth around the anus. 



The calcareous deposits form two layers : The inner layer 

 is very thick and crowded, consisting of thick elliptical plates 

 with smootli margin. The smallest plates have four holes, there 

 being very often a handle-like arch betwc^on the two holes in the 

 longitudinal axis (c). In the larger plates, the four main holes 

 are often eccentrically situated, in which cases the arch is also 

 eccentric in position and lies longitudiiKilIy l)etween the two 

 main holes in the longitudinal axis. Somc! plates in the layer 

 are of an elongate shape ; these show foni' main liolcs in tlie 

 middle broad parts, besides having some more holes in a row in 

 the narrower ])rolonged parts {d, e). The supporting rods of the 

 pedicels are mostly of this form. They have a sort of tower in 

 the middle. In the outer layer the calcareous deposits are not so 

 closely packed together as in the inner layt^r. They are bodies 

 whicli naay best be called reticulated ellipses (/>). They all have 

 an elliptical basal plate with four oi- more distinct holes ; from 

 any spot in the periphery of this basal plate, there may arise 

 several smootli, slender rods. These braiicli, ami the branches 

 fuse whenever and wherever they come into touch. The result 

 is a basket-like table with a very complicated tower, the 

 appearance from above being siin})]y that of a bush consisting of 

 small branches with smootli tips. All stages of development may 

 be observed. 



This species seems to be a northern one. It is known by 

 the name of " Ishiko " in Prov. Owari. 



LocaliUj : — Vancouver's I. (Theel '8G) ; Piiget Sound (Cl.vkk '01) ; Piicific 

 (ti-ovc, Oal. (Oi.AUK '01) ; Pacific coast of Japan from Hokkaido to Prov. 

 Sliinia. 



