BY THE REV. R. L. KING, B.A. 165 



In the next species to be noticed we shall observe a return in 

 some degree to the remarkable unity of form observable in the 

 legs of the Phylloj^oda. 



EURYCERCUS COOKII. 



Of the Lynceidce, I described, in the Transactions referred to, 

 twelve species belonging to the genera Eurycercus Ghydorus and 

 Alona of Baird, and Dimhevedla, a new genus. These genera 

 must be considered as merely provisional, being all founded upon 

 the shape of the carapace, and, in some instances, that of the 

 last segment of the abdomen, without any reference to that of 

 the branchial legs. Hence our present species will come under 

 the same generic name with the large European species 

 Eurycercus lamellalus (Baird), notmthstanding a remarkable 

 difference in the branchial legs, as, for example, the last leg of 

 E. lamellattis is rudimentary, whilst that of E. Goohil is as well 

 developed as the rest. 



The present species is the largest hitherto discovered of the 

 Australian Lynceidce. I obtained it from a large pond among the 

 Botany swamps, and have also received it from the neighbourhood 

 of Brisbane. It usually feeds near the edge of the pond ; but at 

 the approach of an intruder it swims out in a wavy line towards 

 the deeper water, when its size and deep chocolate colour render 

 it an easy prey. 



Plate XIII. contains a correct representation of the details 

 of the anatomy of this very interesting foi'm. The other parts 

 resemble the figures in Mr. Baird's plate of E. lamellatus so 

 closely that a description would be but a repetition of his 

 account. My drawings of the branchial legs are, however, 

 very difierent to his. Each leg consists of two parts, the outer 

 part, probably devoted to purposes of respiration ; the inner in- 

 tended, like the inner lobe of the Phyllopoda, for conveying food 

 to the inouth. 



An inspection of the Plate will at once point out the remark- 

 able resemblance existing between all the legs, except indeed the 

 first pair. The wide branchial plate exists in all, canying the 

 curious stout plumose sette and protecting the haii'less lobe ; on 

 the inner side the lobe next the branchial plate is variously mo- 



