DESCRIPTION OF SPECIES— POTAME^. 101 



coal; rare at Golden. I have also referred to this species, with doubt, how- 

 ever, a few fragments from six miles above Spring Canon, in the collection 



of Dr. Hiujden. 



Caulinitcs fecundus, Lesqz. 



Plate XIV, Figs. 1-3. 



CatiUnitea fecundus, Lesqx., Aunual Report, 1872, p. 384. 



Brancbcs of racemes two millimeters wide, smooth, inflated along the borders, divided in opposite, 

 erect branchlets, half as thick, bearing on each side, and on short pedicels, simple round capsules inflated 

 as by a central nucleus. 



It is very questionable if these fine fruiting branches may be referred to 

 this genus. They have this in common only: a monospermous (?) nucula with 

 a cellulose envelope. As I have been unable to find either in the fossil species 

 described until now, or in the collection of living plants which I was able to 

 overlook, anything to which they had an apparent relation, I have left them 

 in this as yet vaguely defined genus. The disposition of the nutlets along a 

 narrow branch like a common racliis has some likeness to that of Potamoge- 

 ton. The capsules are mostly opposite, close to each other along the branch - 

 lets, twelve or more on each side of an elongated common pedicel ; one and a 

 half millimeters broad, flattened, but with a convex center marked by a slightly 

 smaller nucleus represented by a vesicle of coaly matter easily separated from 

 its envelope (figs, la and 1 6, enlarged). The fragment in fig. 2 represents the 

 lower part of the raceme; it is narrowly, distinctly lineate in the length; but 

 the divisions are smooth, with slightly inflated borders, as in the large middle 

 branch of fig. 1. Fig. 3 represents a flattened linear fragment of a rootlet 

 apparently detached from a rhizoma, as seen from the half-rcund scars which 

 it bears near the upper end. These may be scars of smaller brandies diverg- 

 ing around and from the axis, as in the former species. This fragment 

 seems positively referable to the one described here, as no other kind of fluvial 

 remains of plants were found in connection with it. It is lineate in the 

 length, the lines regular and equal, crossed in right angle by narrow wrinkles, 

 and thus has a facies similar to that of the stem (fig. 4) of the same plate. 

 These racemes might represent the fruiting part of the former species (?). 

 As remains of Palms were found in connection with them, they may be 

 also the undeveloped flowers of some Palm. In the fourth volume of 

 the Arctic Flora, Prof. Heer describes and figures, from the Jurassic of East 

 Siberia, as a Fern, Thyrsopis Maakiana (p. ol, pi. i, figs. 1—3), which has, 

 by its fruiting pedicels, a remarkable likeness to this species of the Lig- 



