Vou. IIT] VAN DENBURGH-—NOTES ON ASCAPHUS 263 
fontanelle. The prefrontals are fairly large, and touch the 
fronto-parietals. The quadrate is rather small. The squa- 
mosal and pterygoid are well-developed. The inner process of 
the pterygoid reaches the anterior surface of the auditory cap- 
sule, while the anterior process passes forward with the 
maxilla to meet the palatine. The parasphenoid extends for- 
ward anterior to the palatines; its lateral processes are well- 
developed, and reach nearly to the border of the large fora- 
mina in the auditory capsules. These capsules extend laterally 
3.5 mm. from the mid-line of the skull; each displays at the 
posterior and inferior aspect of its lateral portion a foramen 
1 mm. in diameter, covered by a delicate membrane, the 
fenestra ovalis. The membrane, however, may be heavily 
covered with a deposit of the chalky material which is found 
in the cavity of the auditory capsule. I have not found any 
evidence of eustachian tubes. The lower jaw is entirely with- 
out teeth. The upper jaw bears a series of very small teeth. 
There are two small rounded patches of vomerine teeth. 
The shoulder girdle is arciferous, the right side lying on the 
ventral surface of the left. The clavicles are well ossified, but 
little curved, and meet medially. There appears to be no omo- 
sternum. ‘The coracoids are rather short (3 mm.) with ex- 
panded ends. The precoracoid cartilages are narrow, but the 
epicoracoid expansions are very broad. ‘The scapula is rather 
small, completely ossified, and broadly fused with the clavicle. 
The suprascapula is composed of two portions: an anterior 
bony bar 4.5 by 1 mm., narrowing to .6 mm. at its middle; 
and a broad cartilaginous plate, 5.5 by 4 mm. in greatest di- 
mensions, bordering the bony bar above and posteriorly. 
The metasternum has been injured in preparing the speci- 
men, but it appears to have been a simple transverse bar of 
cartilage. 
The humerus is 10.5 mm. long. -It bears a very strong 
proximal crest, and the condyloid ridges are so largely de- 
veloped that the breadth of the humerus in this region is 3 
mm., while in the middle of the shaft it is only 1 mm. 
The radius and ulna are completely fused into a single 
bone 7 mm. long. 
The carpus is composed of an ulnare, a radiale, a radial 
and an ulnar centrale, and four distal carpals. 
