410 Dr. F. Miiller on the Darwinian Hypothesis 



C. intermedia occurs also in Mr. Charles Moore's collection of 

 British Carboniferous Entomostraca. 



11. Cythere Muensteriana, n. sp. PI. XX. figs. 11 a, 11 b. 



Length T ' T inch, height -^ inch. 



The specimen from which we describe this species was sent 

 to us as Bairdia elongata, from which, however, we are satisfied 

 it is distinct. 



It is nearly three times as long as high, and has a flatly convex 

 dorsal border, abruptly sloping towards the obtusely pointed 

 extremity ; the other extremity is subtruncate ; the ventral border 

 is somewhat hollow ; the valves are rather flat, thickest near the 

 middle, and slope gently away to each extremity. 



As a summary of Miinster's species, we may add that — 



Minister's No. 15. Cythere O/ceni = Leperditia Okeni (comprising 



L.subrecta and many others). 

 „ 16. C.suborbiculata=L. suborbiculata. 



„ 17. C. inflata =Cytherella inflata. 



„ 18. C. Hisingeri = Bairdia Hisingeri (comprising 



B. Schaurothiana). 

 ,, 19. C. elongata = B. elongata. 



„ 20. C. bilobata —Cythere bilobata. 



„ 21. C. subcylindrica=Bairdia subcylindrica (com- 



prising B. gracilis). 

 j, 22. C. intermedia —Cy there intermedia (comprising 



C. subreniformis) . 



All of these, except B. elongata, we know to be more or less 

 abundant in the Carboniferous strata of Britain and elsewhere ; 

 and some are Permian " recurrents." 



XLIV. — The Darwinian Hypothesis supported by Observations 

 on Crustacea. By Fritz Muller, of Desterro. 



Under the title of ' Fur Darwin/ Dr. F. Muller has published 

 a series of careful and minute observations on certain forms of 

 Crustacea, which, he thinks, furnish a means of testing the 

 soundness of the Darwinian hypothesis. Whether the facts 

 described by him have really the bearing which he attributes to 

 them may be a question ; but there can be no doubt as to the 

 value and interest attaching to his observations. The following 

 abstract of some of the more important portions of this work is 

 derived from the notice in the ' Bibliotheque Universelle/ 1865, 

 "Bulletin Scientifique," p. 154. 



According to Darwin's theory, the natural classification of 



