62 



THE INVERTEBRATA 



Giardia {=Lamblia, Fig. 51). (Diplomonadina.) Shaped like a half- 

 pear, broad end forwards, with, on flat side, a concavity for adhesion. 

 Organization as Hexamitiis but all flagella in middle or hinder region. 

 Parasitic in intestine of man and other mammals. 



Trichonympha (Fig. 52). (Hypermastigina.) Body narrower in 

 front than behind ; provided with very numerous flagella arranged in 

 three distinct sets; without gullet. At the front end is a papilla. The 



Fig. 52. A diagram of the structure of Trichonympha campanula, showing a 

 portion of each layer. From Hegner and Taliaferro, after Kofoid and Swezy. 

 alv.l. alveolar layer; ant.fl. anterior flagella; ba.gr. rows of basal granules; 

 ce. point at which the spindle arises in division ; chr. chromatin granules in 

 nucleus; ecp. ectoplasm; enp. endoplasm; f.b. food bodies; lat.fl. lateral 

 flagella; long.my. longitudinal myonemes; nii. nucleus; obl.f. oblique fibres 

 (rhizoplasts) ; ^eZ. pellicle ; ^05^.^. posterior flagella; surf.rdg. surface ridges of 

 pellicle; tr.my. transverse myonemes. 



ectoplasm, thin behind, is strong and complex in the fore part of the 

 body, where it is composed of the following layers: (i) a pellicle, 

 sculptured into longitudinal ridges, (2) a layer containing longi- 

 tudinal rows of the basal granules of the flagella, (3) a layer containing 

 a network of rhizoplasts ('* oblique fibres"), (4) an alveolar layer, (5) a 

 layer of transverse myonemes, (6) a layer of longitudinal myonemes. 



