186/.] PROF. W. LILLJEBORG ON HALCROSIA AFZELII. 717 



Halcrosia frontata. The edges of the jaws are strongly sinuated ; 

 and the upper jaw has on each side a deep hollow, to receive the 

 seventh tooth of the lower jaw, which in this instance is the largest, 

 and its two foremost front teeth do not pass through the intermaxil- 

 lary bone. The teeth are j^Ei{- Th^ back teeth of the under jaw 

 do not project in between those of the upper jaw, but within them, 

 as in the case of the Alligators. 



Fis. 2. 



Hind foot of Halcrosia ufcelii. 



Onr specimen being imperfect, we have, as regards the feet, the 

 opportunity of examining only one of the hind feet (fig. 2). The 

 web is well developed, but the exterior edge of the foot is not fringed. 

 It has but one row of four somewhat large keeled scales, which do 

 not form any prominent lobe or fringe. The remainder of the outer 

 side of the foot is covered with keeled scales of various sizes. 



With regard to the plates of the skin, this genus, as is known, is 

 especially distinguished by the peculiar form of the upper plates of 

 the nape. These have also in this species a characteristically broad 

 form, with almost horizontally outstanding keels, and are particularly 

 large ; but there are but two pairs, and a considerable interval sepa- 

 rates the posterior from the anterior dorsal plates ; they have iu the 

 middle of their upper surface a shallow longitudinal groove. The 

 cervical plates are six in number, forming a curved transversal row, 

 and are oval and strongly keeled. The dorsal plates form four con- 

 tinuous longitudinal rows, of which the outermost on each side is 

 distinctly, the inmost indistinctly, keeled ; there is, moreover, on each 

 side a couple of imperfect rows, and several scattered plates on the 

 sides of the body. The back and loin have eighteen transversal rows 

 of plates, including the foremost exceedingly small ones. The tail 

 has twelve similar rows between the base and the strongly projecting 

 serrated lobe, or crista. All these plates are as it were sculptured 

 with fine concentric raised lines, as is also the case with the plates of 

 the head and feet. As the end of the tail is missing I am unable to 

 give the number of plates in its crista. The ventral plates are ossified. 

 The colour is indistinct, but seems to have been a very dark brown. 



