154 FIELD COLUMBIAN MuseEuM—GEOLOGY, VOL. II. 
a “ x 3 zg 
: 2 : 2 So 2 
ve a5 F 33 a 8 
es so go. E bo 3S 3 
a ond Of 5. Fs 5 
Z. Z Zz aw A Ay 
FLiumMerus--) a2 oe -- see LO 100 100 100 100 100 
Wind nies: oe ees 165 165 “is 136 148 153 
Metdcarpal se ee 257 275 oR 210 106 105 
Birst: Pralange es. wee 324 327 eos 268 161 160 
Second: Phalange-o---22- Beret 2A Ay = 172 142 129 
B@mur 2230. 2 sae ea 93 93 4 ee 106 109 107 
Diblavc42tete ge tee ere 151 151 eae 150 153 144 
Meétacarpal<ee eee ee 100 100 100 * ee. sive 
Cina Se eee eee 64 60 62 ee pee Atay 
Fifsty nalanye wey serra ee 126 11g 115 on ein. ae 
It is observed that there is a striking agreement in these specimens, 
except in the metacarpals, the differences elsewhere being scarcely more 
than one might expect in the measurement of bones differently affected 
by the compression to which they have been subjected. Now, we may 
consider this variation of specific value and give to each of these three 
specimens a different name; or we may, as is far more reasonable, 
consider the metacarpal as a variable bone in the individual, as it is 
in the species and groups, and refer them all to one species. This 
I have no hesitation in doing. There is, then, but a single species 
of Wyctosaurus now known among the specimens referred to the genus; 
it should be called Wyctosaurus gracilis Marsh. 
In specimens of Preranodon ingens there is noi a little variation in 
size, especially in the length of the wing metacarpal, which I have 
observed to vary from 580 to 615 millimeters, the longest that I have 
ever known from the Kansas chalk. It is very certain, I think, that 
absolute identity of size cannot be relied upon to distinguish the differ- 
ent species of pterodactyls, nor do I think that the relative or propor- 
tional lengths of the finger bones should receive too much weight; 
the different species evidently varied individually within certain limits. 
In my first paper on JVyctosaurus, I discussed briefly the so-called 
species of Pteranodon, P. nanus, and P. comptus, suspecting that one or 
both of them belonged with WVyctosaurus. 
A wider acquaintance with Kansas pterodactyls, both in the laboratory 
and in the field strengthens my belief that both of these names are 
synonyms of WV. graciles. 
No small species from the Kansas chalk can be referred definitely to 
Pteranodon, so far as my own knowledge goes, and I have seen hundreds 
of specimens. /. manus presents the strong lateral crest of the humerus 
which I am satisfied is a diagnostic characteristic of Pteranodon. Al- 
