ECHINUS. 137 



Plate XXXIII. 



Fig. 4. Shell divested of the spines, ujjper surface. 



5. Under portion of the shell divested of the spines. 



6, 7. Suckers enlarged. 



8. Disc of the sucker, magnified. 



9. Paddle-shaped spines. 



10. Echinus pusillus {Echinocyamus), shell, back after nature. 



11. Front. 



1 2. Surface of fig. 1 0, enlarged. 



It is rather from compliance with the usage of modern naturaUsts, 

 than from conviction of its utihty, that I have introduced the subject 

 of the present section under the name and character oi Echinodcrmafa. 



Possibly, my researches being hmited, I have viewed such an ar- 

 rangement on too confined a scale to allow its full scope and effect : yet 

 there appears little reason to expect either its general adoption, or its 

 stability. 



Nothing could be productive of greater convenience, indeed, than 

 the permanent concentration in groups, or families, of the innumerable 

 animated beings dispersed throughout the universe. 



But the union must be founded on features pointed out by Nature, 

 distrusting those the arbitrary choice of mankind. 



Though Natui-e does not always speak in intelligible language, — in- 

 telUgible at least to our humble capacities, while disguised by metaphor, 

 redundance, or defect, — let us persevere in patient investigation, awaiting 

 explanations, sometimes reluctantly given. 



To sanction the formation of groups or families, the relation of ani- 

 mals should be seen in prominent features, readily and unequivocally 

 exposed, even to grosser sense. Here, the majority of observers will 

 be better satisfied with finding sufficient external distinctions, than being 

 remitted to a search for such mysteries as dissection may reveal. 



We cannot confidently affirm that those definite conditions, consti- 

 tuting a separate group, subsist in the preceding species ; that some pro- 



s 



