Closterina.'] infusceial animalcules. 179 



Family— CLOSTERINA. 



The animalcules of this family arc polygastric, or to all appear- 

 ances 80, and destitute of an alimentary canal. Then- bodies are 

 unvarjdng in form, and without any appendages. Like the Crypto- 

 monadina, they are enclosed witMn loricated envelopes, which simul- 

 taneously with theii" bodies, undergo incomplete self-division, so as 

 to form polypi-shaped clusters, of a wand, thread, or fusiform figure. 

 Each individual is fm-nished with a papilla, or sort of nipple, wliich 

 protrudes, but very slightly, through an aperture in the shell, and 

 serves as an organ of locomotion. 



The envelope, or lorica, investing these creatures, is of the form of 

 a little pitcher (urceolm), and either of a yellowish colom", or coloui-- 

 less. In many of the species it is open at both ends. The animalcule 

 itself is a very delicate mucous body, clear as crystal, and often con- 

 tains -nithin it vesicles and green granules, which latter are most 

 probably ova. The locomotive organs appear to be veiy short, 

 slender, and conical-shaped papilloe or nipples, of a transparent hue, 

 placed just within the opening of the lorica, and but very slightly 

 protuding from it. The small vesicles observable among the green ova 

 are, according to Ehi'enberg, belong to the polygastric apparatus. 



As several eminent botanists have considered the various species 

 included in this family, and the family Bacillaria, as belonging to 

 the vegetable, and not to the animal kingdom, I have transferred the 

 generic and specific descrij^tions to Section 1 of the family Bacillaria. 



It should be borne in mind, in treating of this matter, that the 

 descriptive characters of the Closterina, and the illustrative drawings 

 of them, will not be in the least reduced in value or interest, whether 

 these organisms are considered as forming a portion of the animal or 

 vegetable creation. 



To the microscopist the members of this family possess much in- 

 terest, arising from the cu'culation of the particles within the shell 

 neai' the ends, and also along the sides. For these observations an 



