(i42 ])[{. J. W. DAWSON OX KlfKCT TUllHS CONTAINlXd ANIMAL 



I have dedicatecl the ironus to Pnifessor AxTOX Furrscn, wlio Ins so al)ly ilhistrated 

 the carhonlferou.s and peniiian I'atrat'hians of 13i)lieiiiia. 



Bones of tlie head very sninoth, having only a few microscopie punetures. Teeth 

 conical, soniewliat ol)tnse, striated at the inner side of the apices ; there are ahont 

 thirty in each ramus of tlie mandible, and about twenty-seven in the maxillary bone. 

 As in the other Mivrus'iiiriiA, tluy are implanted in a furrow. 



Vertebne short and well ossitiwl, three in a centimetre, llibs sti-ong, curved, about 

 1 centimetre in length. 



Limbs robust, the bones better ossified than in any of tlie other species oi' Micro- 

 saiiria. Humerus round, and with a distinct keel on the shaft. Femur with well- 

 fornied articulating surfaces. Tues of hind foot probably five, central ones lono- and 

 slender. 



Thoracic plate of moderate size and somewhat roundei'. Abdomen protected by 

 needledike rods, which are very numerous, and were probablv arranged en chcri'on. 



Length of mandibl(.> (not (juite ]ieifect) . 2'1 centimetres. 

 ,, maxilla 2 ,, 



"'> 1 



humerus i> 



,, lemur 2"4 ,. 



,. radius and tibia . . . .abiuit I ,, 



„ toe of hind i'oot 7 millimetres. 



Eight teeth in 5 millimetres. 



Under the microscope the bone shows small rounded cells with numerous canaliculi. 

 The cells in the hmb bones are a little longer than the others. The teeth are simple, 

 and consist of dentine traveised by un)derately line ;uul somewhat tortuous tubes ; 

 these are nnich cuar.ser than in llijhinomus, but liner than in IlijIvrpftKii. 



l>. Deialrcrpitvii JcKiUaumn, Owkx (Plate 40, figs. 4G to f)!; and Plate 44, ligs. 12a 



to l.",7, except iig. 1^31). 



[OWEX, Juurnal of Cculugicul Society, vol. ix. Dawson, 'Air breathers of the Coal 

 Pei-i'id/ [.. 17; 'Acadian Cu'ology,' p. ;!(i2.J 



Portions of scvei-al sprciniciis of this species are in the new material, but do nut add 

 much to the knowU-dge (,|" its (li.niKtcrs, which have \>rv\\ fidly given by Uwkn from 

 the somewhat c()m[.Iete s].iTiiinns (il)tained by nie in iS.V.t. 



Some interesting fragments ol' cuticle were found in assm-iation with one of the 

 skeletons, ^vhI(ll sli.,\v wyy well ih,. scaly covering of the back :ii,d the lappets and 

 edge-scales of the si,l,..s. These l;ist ].rol)ably formed a border or margin lo the bony 

 scales covering the altdonicn (Plate U), iigs. 4G to aj). 



