82 Albany Museum Records. 



Reference to Figure. 



Fig. 5 Pltitu IV represents a median section of a skull uf Lystrosaurus 

 latirostris, slightly reduced. 



B.O., Basioccipital ; B.S., Basisplienoid ; E.O., Exoccipital ; Eth., 

 Ethmoid; F.M., Foramen magnum; Fr., Frontal; I.P., Intei'i»arietal ; 

 Na., Nasal; Pa, Parietal; P.F., Pineal foramen; Prex., Premaxillary ; 

 P.P., Preijarietal ; Pt , Pterygoid ; Vc, Vomer. 



Oa tliu Therioiloiits in tlii' Albany Museum. \\\ K. IJROOM, M.D., 

 &c. 



Cynognathus Platycep.S, Seeley. 



Bpecimen No. 1. — This is the almost perfect skull which forms 

 the type. The snout is broken off a little behind the canine teeth, 

 and the back part of the skull is slightly crushed, but otherwise 

 the skull may be said to be perfect. The si)ecimen is descril:>ed at 

 considerable length by Seeley (Phil. Trans. Vol. 180 B. 1895, 

 p. 132), and three illustrations are given. Though one or two of 

 Seeley's determinations are very doubtful, the description is on 

 the whole accurate. The illustrations, however, are very unsatis- 

 factory, and though the outlines are fairly correct, little or no 

 attempt is made to show the sutui-es which are mostly distinctly 

 shown on the specimen. The few sutures which are shown on the 

 figures are for the most part incorrectly placed. In figure 29 the 

 scjuanu^sal bone is shown as forming part of the posterior wall of 

 the orbit ; in tig. 28 the sut-ures of this region are shown in an 

 entirely different arrangement. It is those in figure 28 that are 

 fairly correct : those of fig. 29 being entirely wrong, the most 

 anterior part of the squamosal being 12 mm. behind the orl)it. 

 In figure 'M) there i.s no attempt made to indicate the dilterent 

 bones of the palatal region. 



The specimen is of very great value for the light it throws on 

 the structure of th^ palate and the articular i-egions of the 

 Theriodont skull. 



The pterygoids are well developed, forming a large part of 

 the concave hollow behind the posterior nares, and also forming 

 ui)parently the whole of the very large downwardly directed 

 pterygoid processes. I am unable to find any trace of the trans- 



