INFUSORIA 



57 



3. Lembxjs Colin. Body elongate, with a long caudal bristle ; mouth 

 in the middle with the oral groove leading to it from the forward end: 

 in decaying plants; 3 species; marine. 



l/f 



Fig. 03 Fig. 94 Fig. 03 



Fig.Q^—Lcmbadion huUinum (Conn). Fig. 94 — Plcuroncma chri/salis (Calkins). 

 Fig. 95 — Lemhvs injusionum (Calkins). 



L. infusionum Calkins (Fig. 95). Body lancet-shaped, with a taper- 

 ing anterior extremity; a row of contractile vacuoles extends from the 

 hinder end forward; length .07 mm.: Woods Hole. 



Family 8. OPALINIDAE. 



Mouth absent; body oval or elongate: 6 genera, parasitic in the 

 Anura and in worms and mollusks. 



1. Opalina* Purkinje and Valentin. Elliptical Infusoria living 

 parasitic in the rectum of frogs and toads; 13 species. 



0. ranarum Pur. and Val. (Fig. 96). Body flattened; 

 many contractile vacuoles; length .6 mm.: in frogs and 

 toads. 



2. Anoplophrya Stein. Body elongate: in the di- 

 gestive tract of marine annelids and on the gills of 



crustaceans; occasionally free-swimming. 



' "^ Fig. 06 



A. branchiarum St. Length .1 mm.; body flask- opaiina 



shaped: Woods Hole; free-swimming. (*Doflei"n{ 



Order 2. HETEROTRICHIDA. 



Body with unifonn ciliation andean adoral zone along the oral 



groove consisting of cilia fused together to form membranelles : 7 families. 



Key to the families of HcterGtrichicla here described: 



«! Body not in a cup. 

 hi Body not with a crown of long cirri. 

 Ci Body not funnel or trumitot-sliapiMl. 



rfi Body elongated 1. Plagiotomidae 



rfo Body usually oval with a triangular oral groove 2. Bursariidae 



c. Body funnel or trumpet-shaped 3. Stentoridae 



62 Body with a crown of long cirri 4. Halteriidae 



«2 Body in a cup •^». Tintinnihae 



* See "Opalina,' f-j !^I. ^I. Metcalf, Arch. f. Prot., Vol. 1.3, p. 105, 1909. 



