PROFESSOR OWEN ON REMAINS OF A LARGE EXTINCT LAMA 
that of Auchenia ; in Camelus (ib. fig. 3, pi) it is much produced, and is more inclined 
downward, the pair of these processes bounding a much deeper concavity at the lower 
half of the vertebra. 
Both in Auchenia and Camelus the sharp hind border of the process {pi) is concave, 
and directly continued backward into the diapophysis, d. In Palauchenia the hind 
border appears to be less sharp, less concave ; and if this be in any way due to abrasion, 
a more marked difference is plainly inherent; the border, passing backward, subsides 
on the under part of the centrum; the diapophysial ridge (Plate VI. fig. 1, d) is con- 
tinued forward 7 lines above the pleurapophysial one, and subsides midway between the 
pleurapophysis (pi) and the base of the prozygapophysis, z. This process is less ex- 
panded at its articular part in Palauchenia (Plate VI. fig. 1, z) than in Camelus (ib. 
fig. 3, z), and resembles in shape and in the extent of the infero-external strengthening 
ridge that in Auchenia. The notch between the prozygapophyses is wider in proportion 
to its depth in Palauchenia and Auchenia than in Camelus ; the depression above the 
base of the process in both existing genera is greater than in Palauchenia. 
The diapophysis (d) has a long thickened outer border parallel with its base in Palau- 
chenia as in Auchenia ; in Camelus it is more triangular in form, terminating in a thick 
obtuse apex. The anterior outlet of the neural canal of Palauchenia resembles that in 
Camelus , being less elevated than in Auchenia. 
The succeeding cervical vertebrae of Palauchenia (Plate IV. fig. 6, 4 , s, e, 7 ) show the 
same general modifications as in existing Camelidce, due, viz. to progressive expansion 
and shortening of the centrum to the seventh inclusive, to progressive elongation or 
enlargement of the pleurapophyses to the sixth inclusive, to the development of a pair 
of parapophyses on this cervical, and to the suppression of par- and pleur-apophyses on 
the seventh, with the superadded partial articulations (ib. 7, ff) on the hind surface of 
the centrum for the heads of the first pair of dorsal ribs. 
In the minor characteristics differentiating Auchenia from Camelus , Palauchenia 
agrees with the former ; of the instances of which may be noted the following : — the 
shape and greater relative size of the diapophyses {d) of the fifth cervical, the non-con- 
fluence in the sixth cervical (Plate VII.) of the parapophyses (p) with the pleurapo- 
physes (ib. pi), which confluence in Camelus forms a single large deflected plate coex- 
tensive with the centrum. 
Of modifications peculiar to Palauchenia , the thicker, more tuberous and more ante- 
riorly directed pleurapophyses [pi) of the fourth, fifth, and sixth cervicals (Plate IV. 
fig. 6) are rem arkable. In the fourth is repeated the character of the distinction and wide 
interval between the hind terminal ridge of the pleurapophyses (Plate IV. fig. 5, pi) 
and the front terminal ridge of the diapophysis (ib. d) : in the fifth cervical a wide and 
deep depression marks this interval, of which there is no trace in the corresponding part 
of that vertebra in Auchenia or Camelus. In the sixth cervical the bases of the pleur- 
and par-apophyses (Plate VII. pi, p) coalesce beneath the diapophysis (ib. d) in a degree 
