COMPARISON OP LARVAE WITH THE ANNULOSA. 69 



tween all these, therefore, it is not possible to conceive a 

 more beautiful series of representations. Now pass to 

 the Rasorial or Thysanuriform type, the caterpillars of 

 which, as Dr. Horsfield well observes, have their heads 

 beset with horn-like processes ; but " their chief cha- 

 racteristic," as he could not fail to observe, " consists 

 in two very strongly marked lengthened or filiform ap- 

 pendages " at the end of the abdomen. We have already 

 seen that these tail-like processes represent the long tails 

 of the rasorial birds ; and we shall find that Nature again 

 employs this favourite device to designate the rasorial 

 type of the Annulosa. It is among the Annelides alone, 

 of all the aberrant classes of annulose animals, that we 

 find not a few, but the greatest portion, ornamented with 

 fringed crests on the fore part of their body, and long 

 tail-like processes at the other. Among the Annelides, 

 also, we have the largest Annulosa ; while the thysa- 

 nuriform larvae produce the largest of all butterflies. 

 Other analogies might be pointed out ; but the above are 

 so strong, that there cannot be a doubt of the Annelides 

 representing the thysarmriform caterpillars. Let us next 

 compare the class of Vermes, comprising the intestinal 

 worms, with the vermiform type of caterpillars. Here 

 the analogy is no less interesting. The entomologist 

 will recollect that the great distinction of these cater- 

 pillars is the attenuated or pointed form of its two ex- 

 tremities, so that at first sight it is not readily seen 

 which is the head and which is the tail. Now, this is 

 precisely the description of an intestinal worm, where 

 the mouth, if it exists, is so small as to become obso- 

 lete : even minute inspection is necessary before we 

 can determine at which end it is situated ; so completely 

 pointed and uniform are the two extremities. If it be 

 urged, that the shape of the vermiform caterpillars of 

 the diurnal Lepidoptera are broad and flat in the middle 

 of their body, we have only to look to several of the 

 Vermes for an exact representation of this shape. And 

 if it be said, again, that there are no vermiform cater- 

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