242* LAKE SUPERIOR. 



very strong claws, (as in Macronychus) to fit it for clinging to stones 

 in a rapid current. The mesopectus of Eurypalpus is likewise deeply 

 channeled. The elytra are also furnished with three or lour very 

 obtuse elevated hnes. As yet there is but a single species of the 

 genus known. E. Lecontei, (Dej. Cat.) I am not aware that any 

 description has been published of it. 



Thus is settled the history of the transformations of an anomalous 

 form, which has much perplexed naturalists for many years. Its 

 history shows the care with which our investigation should be made, 

 when we are upon unknown ground. But where the homologies of 

 the animal with other aquatic larvae provided with branchia are so 

 exact, it is a little remarkable that its larval character should remain 

 so long unnoticed. The only difference between it and an ordinary 

 larva (either of Coleoptera or Neuroptera) is the prolongation of 

 the dorsal epidermis, to form a shield under which the true body is 

 concealed. Similar prolongations are found in nearly all orders of 

 insects. 



I know not how Dr. Dekay fell into the mistake of considering 

 the elongate palpi as a second pair of antennae : and surely such an 

 anomalous form as a Crustacean with six legs, and a head separate 

 from the thorax, deserved a more careful examination, before receiv- 

 ing a definite place in the system. 



The figure in the New York Zoology, (as the animal is very pecu- 

 har in its form,) bears a certain vague resemblance to what it was 

 intended to represent ; but for all systematic purposes, it is, like 

 nearly all the plates in that part of the State Survey, perfectly 

 wortUess. 



