8 T. G. HALLE, MESOZOIC DEPOSITS AND FLORAS OF PATAGONIA AND TIERRA DEL FUEGO. 
compared with Peninsula Burleigh. The rocks vary much in regard to their consist- 
ence: sometimes they are as hard as in the former locality, sometimes much softer. 
These softer varieties have a yellowish to reddish colour and probably only represent 
a more weathered state: this is confirmed by the fact that the different varieties 
pass over into each other. Among these softer rocks there occurs also a fine-grained 
sandstone which alternates with and passes over into a coarse slate. In this rock 
I found a couple of very poorly preserved plant-fragments. One is a Sphenopteris 
which, as far as the preservation permits of forming any opinion, belongs to the type 
of Sphenopteris hymenophylloides BRGN.; the other is a minute fragment of a sterile 
branch of a conifer. 
Although there is no direct evidence, it is probable that the different outcrops 
of the rocks described belong to the same series and do not differ much in age. 
Owing to the small extension of the outecrops it is impossible to form an estimate 
concerning the thickness of the formation but it does not appear to be very great. 
There is no reason, therefore, to believe in the existence of any considerable differ- 
ence in age between the fossils found at the different localities. It may be possible 
to give a fuller consideration to this question when the shells from Punta Fösil 
have been examined; at present only the fragments of plant-impressions can be 
described. 
Plant-remains. 
Sphenopteris sp. (cf. S. hymenophylloides BRGN.). 
Pl. 5, fig. 26. 
The fragment shown in pl. 5, fig. 26, is evidently a portion of a fern-frond of 
the type of Sphenopteris (Coniopteris?) hymenophylloides Bron. It represents only a 
very small portion of the frond, consisting of the remains of two pinnae still attached 
to a common rachis. It can be seen that the pinnae are long and linear. The pin- 
nules are ovate, with a narrow base, and are pinnately lobed. 'The venation is in- 
distinct. There cannot be much doubt that the fragment represents a species of 
Sphenopteris of the S. hymenophylloides-group. It is possible that it should even be 
referred to this species, but the poor preservation does not permit of a definite de- 
termination. 
Sphenopteris? sp. 
Pl. 5 fesTo, 28 
The little fragment shown in pl. 5, fig. 27, evidently represents a portion of a 
fern-pinna. It has only a length of 7 mm. and bears a few rounded pinnules, of 
which the venation is not preserved. The fragment is naturally undeterminable. 
