25 



Of Gongyliis ocellatns I had eleven series at my disposal, but 

 without any ohier stadia, sncli as P. Q. and R. of Lacerta. As I 

 liad neither a ftill-grown s|)eciraen nor a good illustration of the 

 shonlder-girdle of (Tongyhis, I am forced to describe the full-grown 

 shoulder-girdle from data taken from the literature on the subject. 

 Of the primary shoulder-girdle the coracoid only contains a fenestra 

 princijialis (apart from the canalis nervi supracoracoidei), just as in 

 Lacerta: and fiirtlier the cranial border of the scapulo-coracoidenni 

 shows a deep hollow. The clavicula, viz. the thin medio-caudal 

 portion, according to Siebenrock, has an extremely irregular liorder. 



Emltryo Gongybis oc. T. possesses a blastematic shoulder girdle 

 continuous with the humerus. The diaphysis humeri already contains 

 praechondriiim. No trace of the clavicle is to be seen yet. The 

 vaguely detined scapulo-coracoidenm consists every where of blastema 

 of equal denseness. The sternum lies at some distance from the 

 coracoideum. Thus this embryo, as also Gongylus oc, G. which 

 shows ihe same degree of development, corresponds to Lacerta ag. S. 



The embryos Gongybis oc. A and B are of very nearly the same 

 age. I shall base my description on embryo A on account of its 

 better preserved colouring. The humerus diaphysis contains cartilage, 

 which passes proxiraally over into praechondrium. This continues 

 into the scapulo-coracoidenm, but is there limited to the region 

 bordering on the humerus. For the rest the primary girdle is blaste- 

 matic, only more sharply defined than in embryo T. At this stage 

 the sternal formation (temporary) has practically become one blaste- 

 matic continuum with the coracoid. From the cranial border of the 

 scapula a blastematic clavicular process goes out in a ventral direction. 

 In the dorsal portion of it I found already a small fragment of bone 

 tissue. The scapulo-coracoidenm still forms one compact whole. This 

 embryo thus agrees with Lacerta ag. I. 



Embryo Gongylus oc. D. (embryo C. represents the same stadium). 

 As in Lacerta ag. embryo J., the scapulo-coracoidenm is here largely 

 cartilaginous (scapulo, coracoideum s. str.). Epicoracoid and proco- 

 racoid are still praechondral. Two thinned blastemic parts have 

 appeared; they correspond to the fenestra principalis and to the 

 incisura scapulo-procoracoidea. The latter is closed by a ligament 

 containing praechondrium. The clavicular blastema, as also Ihe bony 

 clavicula lying in it, have become longer (in a ventro-niedial direc- 

 tion). Between clavicula and the praechondral-cartilaginous scapula 

 is a strip which is still blastematic, representing the syndesmosis 

 claviculo-scapularis. 



In the next embryo of Gongylus oc. E. the thinner blastematic 



