S. W. Williston — Restoration of Limnoscelis. 467 



more caudals. Ribs holocephalous ; 

 notarial ribs of the third to sixth 

 vertebrae greatly expanded for sup- 

 port of pectoral girdle ; seventh rib 

 elongated, but stout ; ribs continuous 

 to eleventh or twelfth caudal. No 

 ventral ribs. A vestigial cleithrum. 

 Humerus with stout ectocondyle 

 directed dorsad ; a well - developed 

 ectepicondyle ; entepicondylar fora- 

 men large ; ulna with olecranon ; 

 four bones in proximal row of car- 

 pus, and at least three in distal ; un- 

 gual phalanges short and broad ; 

 femur with prominent trochanter 

 near its middle, the adductor crest 

 high ; astragalus cuboid in shape, rel- 

 atively small, as also the calcaneum ; 

 at least two bones in distal row of 

 tarsus ; phalanges as in front foot. 

 Both front and hind legs short and 

 stout. Length, seven feet. Horizon, 

 Permocarboniferous of El Cobre, 

 New Mexico. 



As regards the habits of Limnos- 

 celis I have little to add to what I 

 have already written. The very long 

 tail has short spines, except at the 

 base, but the chevrons are longer 

 and stouter than I had expected to 

 find them ; and they are, for the most 

 part, more or less flattened at their 

 extremities. The tail must have been 

 somewhat flattened, though by no 

 means compressed as in the croco- 

 diles, unless it bore a carina of horny 

 scutes above. Taking into con- 

 sideration the very short and stout 

 legs with their broad, flattened feet, 

 the absence of claws, the elongate 

 body and tail, it would seem not 

 at all improbable that Limnoscelis 

 was more or less at home in the 

 water, though not strictly an aquatic 

 animal. In much probability it lived 

 in and about the marshes on the mud 

 flats, hiding in dense vegetation, and 

 often taking to the water for pro- 

 tection from its enemies, of which 



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