496 MISS JOAN B. PROCTER ON THE 



Humerals about twice as broad at humei'O-pectoral suture as 

 from apex to apex, or their median suture. 



Pectorals narrow, median suture two-fifths to three-fifths 

 length of median humeral suture. 



Abdominals more or less square, median suture two to four 

 times length of median pectoral suture. 



Femorals very variable, median suture visually longer than 

 median pectoral suture ; posterolateral corners projecting beyond 

 lateral edges of anals. 



Anals. — Ano-femoral sutures slightly oblique, directed for- 

 wards; lateral borders at right angles to them ; median sutures 

 short, each anal cut away posteriorly and ending in a pronounced 

 point of variable shape, the resulting cleft between them forming 

 an angle of 90° to 120°. The width and depth of this cleft is 

 apparently not dependent on sex, as one would suppose from the 

 great difierence in the relative sizes of their tails. 



The inferior surfaces of the marginals which cover the 

 bridges are extremely nari^ow, from three to four times as long 

 as deep. 



Skeleton. 



Besides the complete skeleton of one adult, and the radiographs 

 of the types, a considerable amount of accessory material has 

 been available. An excessively interesting individual, in which 

 development had been arrested at a still earlier stage, decomposed 

 in transit, thus enabling me to use most of the skeletal parts for 

 study. In this specimen the bony plates were as thin as tissue- 

 paper and extraordinarily flexible. Parts of other tortoises 

 also disintegrated and formed interesting checks on the first 

 skeleton. 



Of the young, an X-ray plate shows that the limb-girdles are 

 normal, as in the adult. The structure of the carapace has been 

 studied in a series of six, ranging from 42 to 82 mm. in length ; 

 in these it was dissected off and the inside aspect cleaned. A 

 complete preparation of both carapace and plastron was made 

 from a specimen 60 mm. in length, and the plastron of the 

 42 mm. individual studied, without its removal, from the inside. 



This material was amply sufficient to show the normal structure 

 and development, besides some interesting variations of the 

 skeleton of T. loveridgii, and to form highly interesting com- 

 parisons with other species. 



The word "plate" is repeated after the name of each dermal 

 bone, in order to distinguish them from the epidermal shields of 

 the same names. 



The hony carapace of the adult. 

 In general appearance the bony carapace is extraordinarj'. 

 Such portions of the neural and costal plates as are present, are 

 formed of translucent bone, and when damp are springy and 

 flexible, making it possible to depress or elevate the carapace as 

 if it were supported upon springs. 



