THE MICROSCOPE 



LIB! 

 NEW 

 BOTA 



OAK 



JANUARY, 1894: 



Number i3. 



New Series. 



Objects Seen under the Microscope, 



VII. — DISC OF OPHIOCOMA. 

 [pen deawixg.] 

 Ophiocoma is a star-fish of the variety often called brit- 

 tle star or sand star. The discs are calcareous (limy) 

 plates or skeletons, the spines of which make beautiful 

 microscopic objects. Figure 1 is a view from above 

 Cdorsal) and Fig. 2 is a view from beneath (ventral), show- 

 ing mouth aperture, teeth and their plates. These star- 



tishes differ in size, some being as small as the dot on the 

 letter i, and some measuring several inches with disciL 

 nearly an inch across. The "teeth" are to be seen in the 

 center of Fig. 2 and look like the 5 sepals of a flower. 

 These teeth like all teeth of Echini are pronounced as of 

 the most wonderfully elaborate architecture to be found 



