496 DR. J. E. GRAY ON SPONGES. [May 9, 



dia, Pachymatisma, Ecionemia, Alcyoncellum, Polymastia, Haly- 

 physema, Ciocalypta, Tethea, Halicnemia, Dictyocylindriis, Pha- 

 kellia, Microciona, Hymeraphia, Hymedesmia. 2. Spiculo-mem- 

 branous skeletons : Hymeniacidon. 'S. Spiculo-reticulate skeletons : 

 Halichondria, Hyalonema, Isodictya, Spongula. 4. Spiculo-fibrous 

 skeletons : Desmacidon, liaphyrus. 5. Compound reticulate skele- 

 tons : Diplodemia. 6. Solid siliceo-fibrous skeletons : Bactylo- 

 calyx. 7- Canaliculated siliceo-fibrous skeletons : Farrea. 



Order III. Keratosa. Suborder 1 . Solid uon-spiculate kerato- 

 fibrous skeletons : Spongia, Spongionella. 2. Solid semispiculate 

 kerato-fibrous skeletons : Halispongia. 3. Solid entirely spiculate 

 kerato-fibrous skeletons : Chalina. 4. Simple fistulo-fibrous ske- 

 letons : Verongia. 5. Compound fistulo-fibrous skeletons: Auliskia. 

 6. Regular semi-areno-fibrous skeletons : Stematumenia, &c. 7. Ir- 

 regular and entirely areno-fibrous skeletons : Dysidea. 



This paper contains some most valuable observations an the struc- 

 ture of the skeleton or framework of the different genera, illustrated 

 by excellent figures made under the microscope by Mr. Lens Aldous. 



Unfortunately the text is encumbered with a most complicated 

 system of terminology, which renders the descriptions very difficult 

 to understand. The names of the suborders quoted above is a good 

 specimen of this. 



Though this work is preceded by a table of the genera of exotic 

 as well as British sponges known to the author, he does not refer to 

 any of the exotic genera which I have described in the ' Proceed- 

 ings of the Zoological Society ' from specimens in the Museum Col- 

 lection. This is the more remarkable as the Museum Collection of 

 Sponges has been frequently studied by the author ; indeed I placed 

 it at Dr. Bowerbank's disposal, with the understanding that he 

 would make a monograph of all the species of the family, or they 

 would have been named some years ago. 



The same arrangement is adopted in his work on 'British Sponges,* 

 published by the Kay Society ; but one or two new genera are added. 



Dr. Oscar Schmidt, in his ' Spongien des adriatischen Meeres,' 

 Leipzic, 1862, folio, with seven plates, divides the sponges into six 

 families : — • 



1. Calcispongiee. 2. Ceraospongiae. 3. Gumminese. 4. Cor- 

 ticatae. 5. Halichondriae. 6. Halisarcinse. 



Dr. Oscar Schmidt divides the Calcispongice thus : — 



I. Foi'm more or less regular. 



Mouth of tube with simple vertical cilia Sycon. 



Mouth of tube with vertical and horizontal cilia Dunstervillia. 

 Mouth of tube without cilia ... Ute. 



II. Form of sponge irregular. 



The wall of the sponge not perforated Grantia 



The wall of the sponge perforated Nardoa. 



