158 Records of the Indian Museum. [Vol. Ill, 



basal pore, which was circular, measuring about o"75 mm. The 

 external surface was smooth on the upper half of the column, longi- 

 tudinally plicated to a slight extent on the basal half. Most or all 

 of the mesenterial spaces appeared on the external surface as slightly 

 elevated ridges separated from one another ])y narrow grooves, 

 which represented the mesenteries. There were no apertures of any 

 kind on the sides of the upper parts of the column; but near the 

 base I have been able to detect a number of minutely microscopic 

 circular pores. These have no swollen lips and do not appear to 

 function as cinclides. The external cilia are short and feeble. 

 There is no protective sheath, and the secretion of the ecto- 

 dermal gland-cells is by no means profuse. 



Peristome. — The most remarkable feature of the peristome is 

 the almost entire absence of tentacles. An examination of living 

 material failed to reveal an}- trace of these organs ; but in speci- 

 mens preserved in spirit they can be seen to exist as minute rudi- 

 ments, which to the naked e3^e or under a hand lens appear as a 

 single circle of white' dots, one at the upper extremity of each 

 mesenterial space, that is to sa}^, 24 or 26 in all. These dots are 

 situated round the periphery of the peristome. They are imper- 

 forate and so minute that it is barel}^ possible to see them in profile 

 with the aid of the most powerful hand lens. They are only visible 

 owing to their greater opacity, which is due to the fact that each 

 represents a reduplication of the body- wall, or rather a micros- 

 copic hollow outgrowth. Their structure appears to be in no way 

 differentiated from that of the surrounding parts. 



The peristome itself is nearly flat in fulh' expanded speci- 

 mens, but when the muscles of the column are contracted it is 

 usually concave ; sometimes, owing to a partial evagination of the 

 stomodseum, it becomes highly convex or even conical. 



The lips of the mouth are by no means tumid and do not appear 

 to be capable of very close juxtaposition. The upper extremity 

 of the ciliated groove of the stomodseum is represented at one end 

 by an expansion, which in some cases is nearly circular. The 

 mouth occupies the greater part of the diameter of the peristome 

 in one direction and is rather narrow in the other ; its two ends 

 are about equidistant from the edge of the peristome. 



Body-wall. — In a transverse section through the bodj^-wall 

 the ectoderm is seen to consist of the elements commonly found 

 in the ectoderm of the Actiniaria. The epithelial cells bear very 

 short cilia. Gland-cells are, as usual, of two kinds, one more 

 elongated than the other ; but both are somewhat scarce. Sense- 

 cells, each bearing a rather stout style, are numerous. Nematocysts 

 are extremely abundant all over the surface of the column. They 

 vary greatly in size but are fairly constant in shape and propor- 

 tions. All are rounded at either end somewhat abruptly and most 

 are curved ; the length is about i the breadth, and varies from 

 0"ot62 mm. to 0'042 mm. 



Immediately inside the ectoderm there is a ring of clear me- 

 sogl(]ea, in which minute star-shaped cells and extremely .slender 



