356 Mr. K. Gr. Can-utliers on the 



liyaline, with a di^^cal subapical transverse vein ; posterior 

 tibiaj with tliree spines. 



Type, 7?. cultellator, Walk. 



JRemosa cultellator. 



Dictyophora cultellator, Walk. List Horn., Suppl. p. 62 (18-58). 

 Ilab. St. Domingo. 



]\Ir. Otto H. Sweezey, in his recently published ' A Pre- 

 liminary Catalogue of tlic described Species of the Family 

 Fulgoridse of Nortli America, north of Mexico/ has included 

 the genus Nonopsis, Spin., in the Dictyo])harinfe. ^ Stal, 

 however, to whom he gives a reference, placed it in the 

 Tropiduchinge, and Uhler also places it in the same subfamily. 

 1 have no personal knowledge of the genus. 



LII. — The Primary Septal Plan of the Rugosa. 

 By R. G. Carruthers*. 



[Plate IX.] 



There has been of late years a revival of the long-dormant 

 discussion as to the presence of four or six primary se])ta in 

 the Rugosa. It would be, perhaps, as well to indicate briefly 

 the reasons for the investigation of a point which may possibly 

 seem of subordinate importance. 



While most members of the Zoanthariu have ahexamerous 

 or dodecamerous primary plan, certain others, such as 

 Edicardsia, have an eight-rayed arrangement. By common 

 consent the latter is regarded as the more primitive type, and 

 most zooids, whether hexamerous or not, are said to pass 

 through an Edu-anhia stage ; in all cases, so far as it is 

 known, the iundamental plan, when not of simultaneous 

 formation, is arrived at by an insertion of bilateral pairs 

 proceeding in a common order. It is a question whether this 

 octamerous plan is genetically connected with that of the 

 llugosa, an extinct group of Palaeozoic corals, commonly 

 sujiposed to be primarily tetramerous, but whose other 

 characters link them with the hexamerous Madreporaria ; 

 but the very slight amount of actual investigation of the early 

 stages in these ancient corals has been a bar to their pliyio- 

 genetic classification, and their relations to other Anthozoa 

 have remained doubtful. 



• Communicated by permission of the Director of II. M. Geoloeioal 



