82 VERMES. 



The tendency of the species to rupture into fragments is very singular. 

 I doubt not that regeneration as perfect beings would ensue with all in 

 the progress of time. 



Herein is found a definite analogy, establishing the kindred of worms 

 of the Gordius tribe, indented by a marginal groove of the anterior, and 

 distinguished by a slit as the mouth in the under surface. 



Unless for this latter character, the last species described might be 

 comprehended in the genus Polia, proposed by Professor Delle Chiaje. 



PLATE XI. Gordius spinifer. 



FIG. 1. Gordius viridis spinifer. 



2. Gordius purpureus spinifer. 



3. Head of another specimen, enlarged. 



4. Posterior extremity and spine of fig. 2. 



5. Gordius fragilis spinifer. 



6. Gordius fasciatus spinifer. 



7. Another specimen, enlarged. 



8. Mouth in the under surface, enlarged. 



9. Head with black specks, enlarged. 



10. Intestine, discharged on spontaneous division, enlarged. 



11. Fragment. 



12. Fragment. 



13. Specimen, mutilated of the lower extremity. 



14. Lower extremity of fig. 13. 



15. Extremity, as regenerated by fig. 13. 



4. GORDIUS INTEGER. We have seen that different sections may be 

 formed of the group we have named Gordius, though the external dis- 

 tinctions of the animals be faint and few. Yet, if we be not mistaken in 

 the perfection of the parts, which in some respects is problematical, they 

 are sufficient. 



Still a third section remains, which, should it not have been necessary 

 to introduce the subject the more intelligibly, ought properly to have 

 stood the first. 



It would seem enough for distinctive arrangement, that the anterior 

 margin of an animal is cleft ; and another, in addition, terminates by a 



