1 64 Miscellaneous. 



Diplopora cincta, Hutton, but its precise place I am unable to 

 discuss at present. 



The following table sliows the arrangement of the Stegano- 

 porellidffi which I propose : — 



Family Steganoporellidae. 



Genus Smittipora, Jullien. 

 Zocecia with the lower compartment (situated beneath the 

 calcareous lamina) undivided. 

 Type : S. abyssicola^ Smitt. 



Genus Steganoporella, Smitt (part.). 



Zocecia with the aboral compartment divided into two 

 chambers by a diaphragm, the lower of which is connected by 

 a tubular passage with the upper and contains the polypide ; 

 the whole of the upper half of the cell forming a large cavity, 

 closed in by the operculum and membranous front wall. 

 Operculum very large. External ocecia wanting ; represented 

 by an internal chamber. 



Type : S. magnilahris, Busk. 



Genus Thalamoporella, n. gen. 



Zocecia with the lower compartment divided ; from the 

 centre of the anterior extremity of the lamina a narrow calca- 

 reous wall is carried up to a level with the margin of the cell, to 

 which it is united, forming an orifice, Avhich is partially closed 

 by the operculum ; on each side of it a large foramen. Oper- 

 culum small, semicircular. Ooecia external, bilobate. 



Type : T. Eozieri^ Audouin. 



MISCELLANEOUS. 



On the Class Podostomata, a Grouj) embracing the Merostomata and 

 Trilohites. Bj' A. S. Packard. 



In a paper read iu November 1885 before the National Academy 

 of Sciences we have endeavoured, by giving the history of the 

 Xiphosura, Poecilopoda, and Gigantostraca, to show that while tho 

 name Xiphosura should be retained for the suborder of which 

 Limulus is the type, the names Poecilopoda and Gigantostraca have 

 been applied in such different senses that they cannot well be 

 retained for the Merostomata and Tiilobita taken together in the 

 sense we advocate. AVe have therefore proposed the term Podosto- 

 mata for this class of Arthropoda. It is derived from novs, frodos, 

 foot, and rrrof^m, mouth, in alhision to the foot-Uke or ambulatory 



