184 C^. HEHBKRT FOWLER. 



and in pai'ticalar did not show the characteristic structure 

 which, for want of a better word, I have termed the " float," 

 He was therefore kind enough to give me permission to 

 describe the animal in detail, a permission for which I beg 

 here to express my thanks. In the hurry of work at sea these 

 small and transparent organisms escaped notice ; they were 

 neither examined alive nor specially prepared for histology. 

 I can, therefore, only hope that the present bald and incom- 

 plete description may be supplemented by some one with 

 leisure and opportunity to study the living material, notably 

 as regards that bewildering complex, the phteodium. 



For purposes of description the organism may be divided 

 into the shell, with shell-mouth and arms, the float, the 

 central capsule and intra-capsular contents, and the phseodial 

 or extra-capsular region. 



The aboral region of the shell (figs, 1 — 3) would be 

 nearly spherical but for a protrusion in the anterior direction. 

 It is homogeneous, and bears minute (and, I think, solid) 

 echinulations. It stains deeply in ha^matoxylin, and appears 

 to be of the same character as the rest of the skeleton, but 

 softer and less resistent to the action of strong alkalies and 

 acids : in raising to alcohols and paraffin it crumples con- 

 siderably. It is transparent and slightly refractile, and I have 

 only been able to detect one layer in the aboral region ; as it 

 nears the mouth, however, it splits into two layers (figs, 4, 8, 9). 

 The shell- mouth is divisible into three zones ; the most aboral 

 of these clearly shows two layers, the inner of which is in- 

 vaginated to form pits, which give it, from outside, a honey- 

 combed appearance. The next zone above this appears 

 externally to be homogeneous, and is perforated by a ring of 

 fine pores, oval or circular, of unequal sizes. The zone of the 

 lip, like the lowest zone, presents a honeycombed appear- 

 ance, due, in this case, to lamina) between the two layers 

 which divide the contained space into irregular polygons, 

 generally hexagons. The actual lip is highest anteriorly, 

 lowest posteriorly (fig, 5) ; the actual opening is circuhir (iig, 

 6), The shell-mouth as a whole is convex or ogival in section, 



