132 



coronoid is a short compressed plate ; the splenial is a longer, slender plate, applied to the 

 inner side of the articular and dentary, and closing the groove on the inner side of the latter. 

 The outer side of the dentary offers a single perforation near its anterior end, which is united 

 to that of the opposite ramus by elastic ligament. 



Purchased. 



629. The skeleton of a large constricting Serpent from Africa (Python regiw, Dum.; 



Boa regia, Shaw*), which measured 15 feet 6 inches in length. 



It had the subcaudal scutes single, as in the American Boas, but it agrees with the Pythons 

 of India in its osteological characters. It presents, for example, as in the skeleton of Python 

 tigris (No. 602), the distinct superorbital bones, with the narrower frontals of which they 

 appear to be dismemberments ; it has also the longer and narrower nasals, the broader ecto- 

 pterygoids, the twisted tympanics, and the lower development of the internal wall of the 

 mandibular coronoid concavity. The prefronto-lachrymals differ from those in the Python 

 tigrif, as well as from those in the Boa, in the absence of the antorbital tubercle. 



In this skeleton there are 348 vertebrae : of which 74 anterior vertebrae have hypapophyses, 

 and all these, save the atlas and axis, have ribs ; 207 vertebrae bear articulated ribs, but have 

 no hypapophysis ; and, of the 67 caudal, 56 have double hypapophyses. 



Purchased. 



630. The skeleton of the Boa constrictor. 



It measures 8 feet 4 inches in length, and, after the atlas and dentata, has 243 vertebrae 

 with moveable ribs, 60 of the anterior of which have hypapophyses, which in the rest subside 

 to a low ridge and tubercle ; there are 60 caudal vertebrae, of which 44 vertebrae have the 

 hypapophyses for the most part in pairs. 



The skull differs from that of the Python in the superior breadth of the frontal bones, in 

 the absence of superorbital bones, in the greater breadth of the nasals as compared with their 

 length, in the more slender and cylindrical form of the ectopterygoids, in the more simple and 

 less twisted form of the tympanics, and in the larger and higher internal border of the coronoid 

 concavity of the mandible. The first caudal vertebra ia indicated by a disproportionate short- 

 ening of the rib, and by a short process from the middle of the outer surface of the rib. This 

 process is longer and nearer to the head in the next rib ; and in the third vertebra the rib 

 seems to bifurcate from its beginning, and has become anchylosed to the diapophysis : beyond 

 the eighth caudal the outer process disappears, but the rib continues anchylosed, and repre- 

 sents a long, transverse, deflected process to within three or four vertebrae of the end of the 

 tail : the zygosphene and zygantrum interlocking with the ordinary zygapophyses are con- 

 tinued to the same extent. The hypapophyses are short, and begin to bifurcate at about 



* " Serpens Pythicus, Africanus, prodigiosus, ab indigenis divino honore cultus." Seba, Thesaurus 

 Rerum Natural, torn. i. tab. 62. fig. 1. In Python Sebee the subcaudal scutes are generally all divided 

 into two : by accidental variety some entire ones may be mixed with the others. D. & B. 404. 



