Only the points in which the cranial morphology of Rana grayi differs from that of the common European species of Rana will be given here.

  • 1
    The anterior process of the crista subnasalis is comparatively long and projects forwards beyond the superior prenasal cartilage.
  • 2
    A ventromedian process of the crista subnasalis appears in the palate, in this way separating the partes palatinæ of the premaxilla and the maxilla from each other.
  • 3
    In the one specimen both the foramina frontalia are absent; in the other the normal condition obtains.
  • 4
    The plica obliqua, which is poorly developed, is suspended from the cartilago obliqua and not from the tectum nasi.
  • 5
    The posterior niche-like portion of the vestibulum is practically absent.
  • 6
    The two Gauppian “Wülste” are both present, but they are not demarcated sharply from each other.
  • 7
    The recessus alaris and the infundibulum are smaller than in the European Rana.
  • 8
    The cavum principale has a small ventromedian recess.
  • 9
    An infundibular vestige of the recessus sacciformis is present.
  • 10
    The musculus lateralis narium is slightly different from that of the European Rana.
  • 11
    A small prechoanal pouch is present.
  • 12
    The septomaxillary consists of an anterior unpaired portion which has three posteriorly directed processes.
  • 13
    The nasals are much smaller than in the common European species of Rana.
  • 14
    A peculiar cartilaginous plate, which is connected synchondrotically to the solum nasi, occurs on the ventral surface of the os en ceinture.
  • 15
    A little further backwards a small cartilaginous cyst appears on either side of the os en ceinture.
  • 16
    Both the parasphenoid and the fronto-parietals are indented anteriorly.
  • 17
    The exoccipital and the prootic do not fuse with each other.
  • 18
    Rana grayi possesses a so-called “Mundwinkeldrüse” situated between the palatal and the facial portions of the maxilla. The gland consists of adenoid tissue and has a lumen which opens into the buccal cavity.
  • 19
    The pterygoid fuses with the processus oticus and with the processus basalis.
  • 20
    In the one specimen the quadratomaxillary acquires a bony connection with the paraquadrate.
  • 21
    A delicate rod-like cartilage, which is connected synchondrotically to the symphysial cartilage, occurs on the ventral surface of the pars mentalis of the dentary.