oO ART. 7. — I. IJIMA : HEXACTIXELLIDA, IV. 



plasmic granules lying against it as well as by the slight but 

 perceptible difference in the staining capacity of the plasma within 

 and without it. Diameter of the nucleus, not more than 2h 

 /i. Flagella, not observed. 



Archœocytes occur either isolatedly or in small flat groups 

 on the outside of the chamber- wall. Size, 22-4 /^ ; exceptionally 

 5 or 6 //. Here as in Euplectella niarshaU'i, one is soon led to 

 the conviction that he has before him small cells, — not nuclei, — 

 unless an inadequate power of the microscope be used for the 

 observation. At least the larger archseocytes are distinctly seen 

 to be composed of deeply stained cytoplasm containing a still 

 more deeply stained nucleus, which is indistinguishable from a 

 trabecular nucleus both in size and aj^pearance. 



Sections of the large specimen are remarkably rich in pecu- 

 liar bodies which I take to represent the thesocytes. We have 

 here to do with clusters of fat-like globules found among the 

 trabeculœ of both the subdermal and subgastral regions. They 

 are shown, not quite successfully, in PL II., fig. 12. The globule, 

 when of large size, may measure 20 !>■ across. Its substance is 

 nearly homogeneous and weakly refractive, taking the stain toler- 

 ably well. It may at times be of a conglomerate-like or of an 

 irregularly granular appearance. Not infrequently a small nucleus 

 is seen in direct contact with the surface ; the appearance then 

 being that the bodies in (pestion are some unusually bulky cell 

 contents or product which has pressed the nucleus of the turgid 

 cell against the external limit. 



Together with the above there occasionally occur smaller and 

 more weakly stained spheres with granular contents. They are 

 shown in both figs. 12 antl 13, PL II., and will be easily recog- 

 nized. In the case of these again I have frequently ascertained 



