56 Introduction to Animal Morphology. 



unequal flagella (Heteronema*). Dinobryon has a loose 

 lorica, and reproduces by continuous gemmation ; hence it 

 appears as a branched colony, each plastide of which has a 

 pigment speck (absent in Epipyxis).f 



Order 2nd. Noctilucae — transparent, phosphorescent, glo- 

 bose, metabolic animals, about -h" -h" • The body has a 

 wide depression on one side (atrium), and a flagellum, con- 

 sisting of a clear cuticle over a closely-transversely-striated 

 axis, arising from a distinct papilla at its base ; near its root at 

 the bottom of the atrium is the mouth, opening into a short 

 oesophagus. On the inner wall of the tube is a ridge, and 

 from its floor springs a long cilium, near which are two brittle 

 rods. The cesophagus ends in a mass of protoplasm, from 

 which numbers of pseudopodia-like threads stretch in a netted 

 manner like a skeleton, to the surface, getting finer as they 

 approach it ; along these threads vacuoles travel from the 

 oesophagus. Outside these threads lies an ectosarc not divided 

 into separate cell areas, but containing regularly disposed 

 nuclei. Reproduction is by fission, j gemmation, § or by con- 

 jugation and encystation, two individuals having approximated 

 their mouths, their bodies become encysted. Another method 

 is by the formation of swarm-spores {Ctenkowsky), the proto- 

 plasm mass segments into 2, 4, 8, &c. On the ectosarc (which 

 becomes saccular) arise surface tubercles, which form a disc 

 or boss, each of these becomes zoospore-like, and moves 

 about by its vibraculum. 



Class 5. Protoplasta|| [Haeckel). — Nucleated plas- 

 tides, having the central granule-, and vacuole-bearing 

 protoplasm (endosarc) surrounded by a firmer dif- 

 ferentiated layer (ectosarc), and often by a cuticle, so 

 that the blunt lobose pseudopodia cannot coalesce 

 when they come in contact (except in Actinophrys). 



* The tail of the ametabolic Phacus is not to be confounded with a 

 second flagellum. 



t Some of these are probably vegetable. 



X Baddeley. § Gosse, Busch, 



IJ Lobosa, Carpenter, 



