102 



THE AMERICi\]Sr MONTHLY 



[June, 



when introduced into a warm-blooded 

 animal — for instance, man. Other 

 individuals will enter the body of 

 early, larval stages of Eubratichipus. 

 Those individuals introduced in some 

 way or other into the human body 

 may enter another life-cycle, and may 

 then find the most favorable condi- 

 tions for their propagation. 



Brachionus Coniura 

 Rotifer. 



BY H. F. ATWOOD. 

 7-lOOOths of an inch. 



-A New 



Fig. 24. — Brachionus coniuvi. 



In a filtering of Hemlock lake- 

 water (Rochester's water supply) 

 made in August of last year, I no- 

 ticed a rotifer that at once struck me 

 as different from any that I had be- 

 fore observed or seen described. On 

 examination it proved to be a Bra- 

 chionus, and a diligent search through 

 the somewhat scattered literature on 

 the subject has failed to indicate 



that this form has ever been descri- 

 bed. 



The Micrographic Dictionary fol- 

 lows the classification of Ehrenberg, 

 while Carpenter, in his work, " The 

 Microscope and its Revelations," 

 adopts that of Dujardin. While all 

 classifications of the rotatoria thus far 

 made are more or less unsatisfactory, 

 that of Ehrenberg seems the least 

 faulty. According to the last named 

 author, I find that this organism, by 

 reason of having its rotatory disk di- 

 vided into two parts {Zygotrocha) and 

 having a carapace, would show that 

 it belongs to the family "Brachionecea." 

 There are five genera in this family. 

 The BrachiomishdiS one eye-spot and 

 a forked foot, and to this genus the 

 rotifer unquestionably belongs. 



Brachionus conium : Lorica, irre- 

 gularly truncate, slightly reticula- 

 ted over the entire surface except 

 the collar, carrying frontal spines ; 

 this latter portion has a hard, vitre- 

 ous appearance. There are ten 

 frontal spines, the middle one on the 

 dorsal surface is longer than the 

 others, and describes almost a right- 

 angled turn, near its centre, to one 

 sidae This spine is half as long as 

 the carapace of the rotifer. Eye- 

 spot prominent. No openings on 

 the dorsal surface of the carapace. 

 There are four posterior spines, 

 one at either extreme side, and one 

 e'ither side of the anal opening. 

 Tail or foot, slender and bifid. Ex- 

 treme length of rotifer, including an- 

 terior and posterior spines, seven 

 one-thousandths (to'o"o) of an inch. 



Unfortunately a dead specimen had 

 to be used for the drawing ; hence, 

 no definite description can be given 

 of the mouth-parts. The external 

 appearance is, however, so strikingly 

 characteristic as to serve all purposes 

 of identification until the internal 

 structure can be fully described. 



I am indebted to Mr. W. M. 

 Rebasz for the very accurate and 

 well-executed drawings of this rotifer. 



