NYCTODACTYLUS.
The type species of this genus was described as follows by its author (loc. cit. supra):
“One of the smallest American species yet found is represented in the Yale Museum by several bones of the wing, a number of vertebrae and the nearly complete pelvis. The wing-bones preserved are elongated and very slender. The pelvis is unusually small, and there are five vertebrae in the sacrum. The last of the series indicates that the tail was short. The following are the principal measurements of this specimen:
| Length of ulna | 187 | millim. |
| Length of metacarpal of wing-finger | 300 | |
| Antero-posterior diameter of outer condyle at distal end | 15 | |
| Transverse diameter of shaft, above condyles | 13 | |
| Length of first phalanx of wing-finger | 347 | |
| Extent of five vertebrae of sacrum | 57 |
This species, which may be called Pteranodon gracilis, was about two-thirds the size of P. velox Marsh. It probably measured about ten feet between the tips of the expanded wings.”
In the December number of the same volume of the American Journal of Science, he described the genus as follows:
“A second genus of American Pterodactyls is represented in the Yale Museum by several well preserved specimens. This genus is nearly related to Pteranodon, but may be readily distinguished from it by the scapular arch, in which the coracoid is not co-ossified with the scapula. The latter bone, moreover, has no articulation at its distal end, which is comparatively thin and expanded. The type of this species is Pteranodon gracilis Marsh, which may now be called Nyctosaurus gracilis. It was a Pterodactyl of medium size, measuring about eight to ten feet between the tips of the expanded wings.”
The specific description of this species rests solely upon the measurements; the other characters given are not only vague, but are also common to all the known species. The generic description, as it is seen, is based upon the structure of the coraco-scapula. It will also be observed that the characters are not drawn from the type specimen, as that did not include this part of the skeleton, according to the author’s statement. Of these two characters, the non-ossification of the coracoid and scapula is a somewhat doubtful one, as the same character may or may not occur in allied species, as, for example, in the species of Rhamphorhyncus (R. Muensteri Goldf.) described by the author himself. So incomplete and unsatisfactory are the characters thus given that Zittel, in his Handbuch, dismisses the genus with the brief remark, “noch unbeschrieben.”
Nevertheless, from the peculiar form of the scapula, and from my recollection of the specimens upon which the genus was based, I believe I have determined with certainty an excellent specimen in the Snow Museum of Kansas University as a member of it, and here give a sufficiently complete description to place the genus on a more secure foundation.