46 BULLETIN OF THE LABORATORIES 



respiration taking place, as in many small entomostraca, through the 

 body surface, and circulation is affected by the rythmical movements 

 of the digestive tube and the ciliary action in the later vessels. 



In mature females much of the body cavity is filled by the ovary 

 and the yolk masses or eggs. The ovary is disc-shaped, botryoidal 

 or variously contoured and in the grey substance exhibits hyaline spots 

 containing the nucleated ovule cells. A part of the ovary temporari- 

 ly secretes the yolk when the egg reaches maturity, so that the appear- 

 ance of the viscera differs greatly at different times. The egg, after 

 extrusion, is commonly carried about in a delicate external brood-sac 

 as in copepoda. 



To add here the details of the development of the egg would lead 

 us too far. The male, as before said, has no functional digestive tract 

 and is not only much smaller than the female, but suffers a reduction in 

 many organs. The sensory organs are, however, well developed. The 

 testis is spindle-shaped or oval and opens in a papilla, which also con- 

 tains the opening of the water chamber or pulsating vessel. The 

 spermatozoa are rod-like or thread-like and motile. 



The Rotifera are found in fresh and salt water over the entire globe. 

 Some species may be found in damp situations on land. They exceed 

 even the lower Crustacea in their great adaptability to changes in out- 

 ward surroundings. Not only is drought not destructive to the eggs, 

 but the animal itself endures a long period of dissication. Other 

 notes upon the habits must find their place under the special descrip- 

 tions. 



Descriptive Part. — As above stated, the following descriptions are 

 given without attempt at orderly arrangement, with the expectation of 

 ultimately attempting a systematic review. In cases where lack of 

 literary aids make positive identification impossible, the description 

 alone will be given, awaiting future identification. 



GENUS FLOSCULARIA, Oken. 



The head is margined by five oval processes bearing exceedingly long setas of 

 excessive fineness. The mouth is central, with a funnel-form opening. There is 

 a crop-like vestibule, separated by a partition from the pharynx, except in the cen- 

 tre, which is perforate, the opening being margined by several pendulous cilia. 

 The adult is attached by a long, jointed foot, but the young is motile and possesses 

 eyes, which are aborted after the metamorphosis. 



