StEPHANOCEROS. 221 



that the individuals examined were adults, as Prof. Slack writes : 

 " two red eyes are found in young specimens, but in adults they 

 either disappear or not conspicuous." 



Stephanoceros is voracious and feed upon a variety of 

 organisms, such as unicellular plants, amniulcules and rotifers. 



Reproduction takes place by means of ova. No ova were 

 detected in the Ottawa examples but in Flossularia, an allied 

 form. I have frequently met the brownish, ganular and oval 

 ovism adhering to the body case. The ova of the latter are 

 generally found attached to the slender stems of myriophyllum 

 or other aquatic plants growing in quiet ponds or shallow bays. 

 They are also found adhering to the fine rootlets of submerged 

 willowj. For the period covering two whole weeks I was able 

 to study the characters and structure and mode of life of this 

 rare and most beautiful rotifer — by being carerul and placing 

 the individuals back into my aquarium immediately after 

 examination. 



Ottawa Hydrachnida. 



KcENIKE, Von F — Zur systematik der GatUing Eylais, Latr- 



Sonder-Abdr. d. Abh. d. Naturw. Ver. z. Bremen, 1897, 



Band XIV, H. 2. 



In this paper, Eylais falcata, Eylais desecta and Eylais tri- 

 angulifera are three Canadian species of Hydrachnida described 

 for the first time by Dr. Koenike, on pp. 288-290. Previous to 

 this most recent study of the genus Eylais, our Ottawa species 

 of Eylais were all referred to E. extendens* by Mr. Tyrrell, in the 

 Report of the Entomological Branch of the Club, and by Dr. 

 Koenike himself in his " Nordamerikanische Hydrachniden." 

 Dr Koenike's present paper evidently subdivides the genus 

 Eylais and the forms described under the designation E. 

 extendens O. P. Muller). 



(i) £". falcata — This species was found in a pond at 

 Deschenes, and in the Rideau, by Mr. Tyrrell. 



*Ti'ans. Ottawa Field-Naturalists' Club, Vol II, No. i, p. 140, 1884 ; and 

 Nordamerikanische Hydrachniden, Abh. d. Naturwiss, Ver. z. Bremen, Bd. Xill, 

 He(t. 2, p. 171, 1895. 



