UODIFIOATIONS OF STRUCTURE IN DECAROD CRUSTACEA. 227 



are represented after being pulled forwards to sonic extent, in 

 order to show the cavity of the prostomial chamber beneath and 

 behind tliem. 



Enough haS; 1 think, been said to justify my view that 

 many of the characters which distinguish the species of 

 Albunea, both from one another and from their allies, are 

 correlated with the function of respiration under areuicolous 

 conditions of life. The verification of this inference must rest 

 with those who have the opportunity of examining these 

 animals alive under the proper conditions. 



It must in any event, however, remain clear that the great 

 problems which Darwin left us as his heritage, after so greatly 

 illuminating them, are not to be solved by the exclusively 

 morphographical researches which occupy the time and zeal of 

 the great majority of naturalists to-day. Even in the best of 

 hands such researches are capable, as I have shown from the 

 history of the forms discussed in this paper, of obscuring even 

 the simple facts of structure which they profess to elucidate; 

 while the study of the functional relations of parts, side by 

 side with the anatomical elucidation of the parts themselves, 

 provides not only the data for generalisations of intrinsic 

 importance, but assistance of an invaluable character in the 

 field of morphological criticism. 



APPENDIX. 



Description of the New Species of Albunea (A. scu- 



TELLOIDES, N. SP.) MENTIONED IN THE FOREGOING PaPER. 



By Walter Garstang, M.A. 



With Plate 14, fig. 5. 



This new species of Albunea closely resembles Albunea 

 microps, Miers, in size, colour (in spirit) and shape. I found 

 a single male individual among a number (placed at ray dis- 



