Annals of the Transvaal Museum. 
215 
Lystrosaurus Jorisseni, n. sp. 
The specimen has suffered somewhat from lateral compression. The 
measurements of the breadth over the prefrontals and between the orbital 
rims have therefore been corrected as far as possible. The breadth over 
the prefrontals is much greater than the length of the premaxillary in 
latirostris , whereas in Jorisseni the reverse is the case. While the 
premaxillary of our form is much shorter, the parietal region appears to 
be absolutely broader than in declivis ; moreover, this species is relatively 
broader between the orbital rims. Alfredi and Breyeri are broader over 
the prefrontals and much narrower over the parietals. Murrayi is rela- 
tively much narrower over the prefrontals. The snout of verticalis is 
relatively much longer, and compared with the breadth over the prefrontals, 
this is also the case with hoops. Frontosus, Andersoni , Mccaigi, and 
Putterilli as with Breyeri. The snout of platyceps is relatively broader 
than in Jorisseni. Measurements (for the meaning of the figures see 
description of Breyeri) : 1 , 73 mm. ; 2 , 36 mm. ; 3 , 62 mm. ; 4, 42 mm. ; 
5 , 25 mm. ; 6 , 65 mm. 
Lystrosaurus Jeppei , n. sp. 
This is a remarkably broad and low skull. It has suffered from 
vertical crushing, and, as a consequence, the measurement of the length 
of the premaxillary had to be corrected. Jeppei has the same breadth 
in the parietal region as the much bigger latirostris , and is therefore 
relatively much broader. Although its premaxillary is much shorter, 
Jeppei is even absolutely broader in the parietal region than declivis. 
Alfredi and frontosus are broader over the prefrontals. Alfredi is, 
moreover, narrower between the parietal ridges, and vlatyceps is relatively 
broader. The orbital cavity of platyceps is also relatively much larger 
than that of Jeppei. The following forms are relatively narrower over the 
prefrontals than Jeppei : Murrayi, hoops, Putterilli, Breyeri, and Jorisseni. 
The snout of hoops and verticalis is longer. Andersoni and Mccaigi are 
relatively much narrower between the upper posterior corners of the 
orbital rims. Breyeri and Jorisseni have also a much longer snout. 
Measurements : 1, 57 mm. ; 3 (not taken into consideration at 
present) ; 3 , 68 mm. ; 4 5 48 mm. ; 5 , 22 mm. ; 6 , 78 mm. 
Lystrosaurus Theileri, n. sp. 
This skull is very much damaged, the premaxillary having been 
wrenched away from its original position and now being situated some 
4 cm. in front of the maxillaries. The whole of the skull top, however, 
is very well preserved. The preparietal is seen to be a narrow elongated 
bone, unlike the shape of this bone in known Lyslrosauri. The suture 
between the frontals and the nasals is bent sharply backwards along the 
median line, the nasals cutting deeply into the front edge of the frontals. 
This also is contrary to the condition of this suture in all other I^ystrosauri 
where it is known. Declivis, latirostris, and Alfredi are all relatively much 
broader over the prefrontals. Boops is narrower over the parietals and 
has a much narrower snout. Frontosus is relatively narrower over the 
prefrontals. Andersoni is relatively broader between the upper posterior 
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