imperfectly -known Species of Corals. 



15 



epitlieca, which, though not thick, is provided with irreguhxr, 

 somewhat sharp- edged, closely-set annulations, and is marked 

 with faint longitudinal or costal ridges. The exterior zone 

 of the corallum for a width of from 3 to 4 niillims. is made up 



Thin sections of Endopht/lhwi CEhlerfi, Nich., enlarged rather more 

 than twice. A. Transverse section of a corallite, showing the outer 

 vesicular zone and the inner tabulate area, the latter intersected by the 

 septa. E. Vertical section of the same, showing the same two areas : 

 the bending upwards of the tabulfe in the outer part of the inner area is 

 here well shown, and the cut edges of a number of the septa, in the form 

 of longitudinal lines, are also exhibited, owing to the fact that the section 

 is slightly excentric ; on the left-hand corner of the figure a part of the 

 exterior vesicular zone has been restored. 



of large-sized, irregularly-shaped lenticular vesicles, which in 

 vertical sections (fig. B) are seen to be directed with their 

 longest axes passing obliquely downwards from the circum- 

 ference towards the internal wall. Their greatest length 

 varies from 1 to 5 or 6 millims. The inner mural invest- 

 ment is well marked, and encloses a space of from 14 to 15 



