POLYPS AND CORALS. 47 



septa and columella .are comparatively well developed, and 

 constitute the entire structure of the coral. 



STEPHANOSEBIS JAPONICA Verrill, nov. 



Corallum low, covering small, univalve shells, like the 

 other species of the genus, somewhat wider at the summit 

 than at the base, with a broad, oval, nearly circular cup. 

 Costas 48 in number, alternately larger and smaller ; those 

 of the first three cycles quite prominent, thickened towards 

 the base, evenly dentate, or strongly granulate along their 

 whole length; the granules or teeth often in two or three 

 rows towards the base, where the costae are thickened. 

 The costae of the fourth cycle are much less developed, lit- 

 tle prominent, with the edges covered by strong, sharp 

 granulations. Away from the base of the coral the shell is 

 covered with rows of sharp, conical granulations which be- 

 come scattered towards its tip and beneath. In one speci- 

 men a young coral rises from this granulated extension of 

 the base, near the point of the shell, apparently by budding. 

 Septa in four cycles, those of the third least developed; 

 those of the first and second cycles very prominent, with 

 rounded summits, and inner edges perpendicular, finely den- 

 ticulate at the top, but having several strong paliform teeth 

 at the inner base ; the septa of the fourth cycle are united 

 in pairs to the primaries and secondaries, at their outer 

 edges, and rise nearly as high, though much narrower and 

 thinner, and thus are formed prominent clusters of three 

 septa, alternating with single septa of the third cycle, which 

 are narrow and little prominent. Collumella less devel- 

 oped than in the preceding species, of a fine spongy texture, 

 occupying about a fourth of the width of the cup. Diame- 

 ter of the largest specimen .25 of an inch ; height above the 

 shell .15; depth of cup .08; projection of primaries .05. 



Kagosima, Japan, in 20 fathoms. Dr. Win. Stimpson. 



This species resembles S. lamellosa in form, but may 

 readily be distinguished by the more strongly toothed and 

 rougher costae, those of the fourth cycle not being so thin 

 and prominent ; the principal septa more prominent and 

 wider ; the columella much finer, less developed, and^scarcely 



