234 



TBOCHELMINTHES 



Fig. 371 



Limnias 



ceratophijlU 



(from Siissw, 



F. Deut). 



L. ceratophylli Schrank (Fig. 371). Tube not anniilated; length 

 mm.; ventral antennae short: on water plants; abundant. 



L. annulatus Bailey. Tube annulated; body with 5 

 horn-like dorsal proccvsses; length 1 mm. 



3. CEciSTES Ehrenberg. Corona a wide oval; lobes 

 indistinct ; tube irregular or absent ; dorsal antenna minute 

 or absent : 10 species. 



0. crystallinus Ehr. Tube variable, transparent, often 

 covered ^vith dirt; ventral antennae small, wide apart; 

 length .5 mm. 



0. melicerta (Ehr.). Two long dorsal projections just 

 below the corona, sometimes antler-like; tube formed of 

 pellets and very short, or wanting : common. 



4. Megalotrocha Ehrenberg. Colonial and sessile, 

 each colony appearing to the eye as a grayish ball; not 

 tubicolous; corona broad, reniform; antennae inconspicu- 

 ous: 2 species. 



M. albofiavicans* Ehr. (Fig. 372). Four opaque warts 

 in a row just beneath the corona; length 2 mm., of colony 

 5 mm. 



5. Lacinularia Scliweigger. Colonial and similar to 

 Megalotrocha but each individual is in a transparent tube: 



1 species. 



L. socialis (Pallas). Length 2 mm., of colony 3 

 mm.: on water plants; less common than above. 



6. CoNOCHiLirs Ehrenberg. Free-swimming pelagic 

 colonies, each individual in a transparent tube: 3 

 species. 



C. volvox Ehr. Colony spherical, consisting of 10 

 to 40 individuals arranged radially; ventral antennae 

 separate except at base; length .6 mm., of colony 1 

 mm.: common. 



C. unicornis Rousselet (Fig. 373). Colony irreg- 

 ular, containing few individuals; a single large ventral antenna situated 

 on the corona : common. 



Order 2. BDELLOIDA. 



Non-tubieolous rotifers (with a few exceptions) which swim with 



the corona and creep like a leech by attaching alternately the front and 



hind ends of the body; body cylindrical, with a cutieula composed of 



rings which can be telescoped; foot usually ending with 3 toes and with 



* Soe ''The Formation of New Colonies of the Rotifer Megalotrocha albofiavicans 

 Ehr.," by F. M. Surface, Biol. Bull., Vol. 11, p. 182. 



g-: 



Megalotrocha 



albofiavicans 



(from Siissw. 



F. Deut.). 



Fig. 373 



Conochilus 



unicornis 



(from Siissw. 



Deut). 



