60 
FOSSIL REPTILIA OF THE 
fested in this character is considerable in the present order, although in no species has any 
departure been observed from the predatory zoophagous condition. The teeth, always 
simple and pointed, vary in shape, in number, in position, in relative size. Pterodactylus 
crassirostris exemplifies the laniariform type of teeth, more or less elongate, and separated 
by intervals of varying extent. In this not uncommon condition the teeth are longest in 
the upper jaw, as offering more resistance than does the lower jaw in aid of the weapons 
most deeply implanted in the struggling prey. 
In Pterodactylus lonyirostris the teeth are rather small, subequal, with short intervals, 
a little widening toward the hind end of the series, which is restricted to the anterior half 
of the jaw, both above and below. 
In some Pterosauria a certain extent of the fore part of both upper and under jaws is 
edentulous, and from its shape has been inferred to have supported a horny sheath. The 
teeth are long slender canines, with wide intervals. They number from about 8 to 10 
on each side of the upper jaw, and from 7 to 8 in each ramus of the mandible. Von 
Meyer proposed for this modification of mouth the generic name Phamphorhynchus. 
DimorpJiodon shows the combination of scattered laniaries, with small, more closely 
set serial teeth in the lower jaw ; it has more numerous teeth, occupying a greater extent 
of the alveolar margins of the jaws, than in any other Pterosaurian. 
The very small teeth which have been observed in the short jaws of the little Ptero- 
dactylus hrevirostris^ are most probably characters of immaturity, not of species. 
In regard to the bony structure of the head and the dentition, the general result of 
observation and comparison of Pterosaurian fossils, and common consent of competent 
investigators, having excluded the volant Mammals from the claim of affinity, the question 
becomes narrowed to whether the skull in Pterosauria more resembles that in the cold- 
blooded or the warm-blooded oviparous air-breathing Vertebrates. 
Hermann von Meyer, who has contributed a great and valuable share to our know- 
ledge of the Pterosaurian order,^ quoting Oken’s opinion, “ that the skull is intermediate 
in character between that of the Chameleon and Crocodile,” sums up his own conclusions 
on that head in the following terms : — “The skull oi Pterodactylus \s, essentially comparable 
only with that of Birds and Samians. The preponderating resemblance with the Bird’s 
skull cannot be contested. Against this, however, is a remarkable dissimilarity in certain 
parts which, on the other hand, approximates it to the type of Samians.” ® 
The term Sauria is here used in the sense of Brongniart and Cuvier, and it is open 
^ Goldfuss, Icc. cit., tab. x, fig. 2. 
2 Especially in the arlmirable summary of his own and others’ researches, in the part of his great work, 
‘Zur Fauna der Vorwelt’ relating to “Reptilien aus dem lithographischen Schiefer,” &c., fob, 1860. 
^ “Der Schadel der Pterodactyln, der nach Oken zwischen Chamiileon und Crocodil stehen wiirde, 
lasst sich eigentlich nur mit den Vogeln und den Sauriern vergleichen ; die iiberwiegende Aehnlichkeit mit 
dem Vogelkopfe kann nicht bestritten werden ; ihr gegeniiber steht aber eine auffallende Uuahnlichkeit in 
gewissen Theilen, die dafiir zum Zypus der Saurier hinneigen.” — Op. cit., p. 15. 
