188 MICROSCOPY FOR BEGINNERS. 



J. Podal spines not forked ; worms living beneath 

 decaying bark of dead trees. Enchytrceus, 2. 



c. Podal spines, six to ten in each cluster, the clusters 

 in two rows. Chcetogaster, 3. 



c. Podal spines, two only in each cluster, the clusters 



in four rows. Lumbriculus, 4. 



d. Posterior extremity without finger -like append- 



ages (e). 



d. Posterior extremity widened, ciliated, with several 

 retractile finger-like appendages. Dero, 5. 



d. Posterior extremity ciliated, with two long, non- 



retractile, finger-like appendages. AuUphorus, 6. 



e. Bristles and podal spines in separate rows (A). 



e. Bristles and podal spines alternate in the same 



row. Strephuris, 7. 



f. Body variegated with brick red spots ; blood col- 



orless. ^Eolosoma, 8. 



g. Podal spines in clusters of four each ; body the 



color of raw meat. Ocnerodrilus, 9. 



g. Podal spines in clusters of two each. Lumbricu- 

 lus, 4. 



A. Worm with two small anterior pulsating hearts ; 

 blood bright red. Tubifex, 10. 



h. Worm without a distinct heart ; dorsal vessel pul- 

 sating; blood red. Ndis, 11. 



1. PmsxfNA (Figs. 134, 135, 136). 



Body nearly cylindrical, transparent, often very long, 

 and showing that it is preparing to divide across the 



