Intelligence and Miscellaneous Articles. 401 



by Prof. Huxley ; and the author now gave diagnoses of Suborder VI. 

 Lepidopleuridce (not equivalent to PleurolepidcB of Quenstedt), in- 

 cluding the following families : — 



1. Platysomida. Teeth uniserial, conical, sharp; palate edentulous. 



Platysomus, Ag., partim. 



2. AmphicentridcB. Dorsal and ventral margins sharply angulated ; teeth 



in the form of tuberculated plates on maxillary, mandibular, and 

 palato-vomerine bones ; prasmaxilla and " prsemandibula " eden- 

 tulous. Amphicentrum, n. g. 



3. Eurysomidcs. Teeth in the form of blunted cones, on a peduncle with 



a constricted neck. Eurysomus= Platysomus, Ag., partim. 



4. Mesolepidce. Teeth similar to those of Eurysomus. Mesolepis, n. g., 



Eurynotus, Ag. 



5. Pycnodontidcs. Teeth oval or hemispherical, or, if elongate, blunted 



cones. Pycnodonts of authors (except the Labroid forms of Cocchi). 



Platysomus ranges from the Carboniferous to the Permian, one 

 species, P. striatus, being common to both, as well as to England 

 and Germany. Eurysomus is Permian only ; the true Pycnodonts 

 exclusively Mesozoic. The remaining families are Carboniferous, 

 while the first three disprove the generalization as to the non-exist- 

 ence of apodal fish before the Chalk. 



5. " Note on the Scales of Rhizodus, Owen." By John Young, 

 M.D., F.G.S. 



Attention was drawn to the fact that, on a slab in the collection 

 of the Pvoyal Society at Edinburgh, the characteristic Rhizodus teeth 

 occur along with thick bony scales whose exposed area is orna- 

 mented with coarse tubercles, usually irregularly disposed, while the 

 overlapped anterior area is concentrically striated. These cha- 

 racters confirm the generic distinctness of Rhizodus from Holopty- 

 chius, whose smooth anterior and rugose free surfaces contrast with 

 those described. 



LX. Intelligence and Miscellaneous Articles. 



ON A GAS-BURNER FOR SOUNDING LARGE TUBES. 

 BY E. REUSCH. 



r pHE gas-burner which I have used for the last two years in pro- 

 -*- ducing from metal pipes, of 2 to 3 metres in length and 7 to 8 cen- 

 tims. in width, beautiful continuous organ-tones, is essentially a wide 

 Bunsen's burner, the upper aperture of which is closed by a wire 

 gauze which is convex on the outside. The dimensions of this 

 burner are as follows. The vertical tube is 125 millims. in length by 

 17 millims. internal diameter; it fits with gentle friction on a solid 

 cylindrical part 25 millims. in height, in which is screwed the jet for 

 the issuing gas. At the lower part of the tube, 12 millims. from the 

 bottom, are four rectangular orifices 12 millims. in height by 6 mil- 

 lims. broad, and to these correspond four slanting apertures in the 

 massive cylinder, by which air can mix with the gas. The part 

 where the gas emerges is 90 millims. below the top of the tube ; 

 with tap and base, the height of the entire burner is 200 millims. 



