DESCRIPTION OF THE SPECIES. 219 



remote or closely placed, varyiiifi;' inuoli in width, viz, from 1""" to 12"""; 

 the maximum length of tlie largest ultimate branches seen, 13""": very 

 prone to break into fragments at the joints and very deciduous ; leaves 

 ver}' short and closely appi-essed, very broadly triangular generally, and 

 but little prolonged above the joint, often seemingly entirely undeveloped, 

 one on each joint, those of the adjacent joints alternating in position ; 

 branches originally succulent and containing but little woody matter : in 

 the ultimate twigs no woodv matter is visible, and they appear to have 

 been composed of a durable epidermis surrounding a fleshy internal portion ; 

 the ultimate twigs unbranched, and seeming to have been very long and 

 comparatively thick. 



Locality : Found onl}' at the entrance of Trent's Reach, and there 

 almost wholly in a layer (J to 9 inches thick near the top of the Potomac 

 beds. 



This remarkable plant is more like Frenelopsis Hohener/ffcri Schenk, 

 than is F. raiiiosissinia. It has larger epidermal tubercles than this latter 

 fossil, and they make lines in the direction of the length of the .stems that 

 are ])lainly vi.siblo to the unassisted eve. This plant has the same long, 

 cylindrical, jointed, ultimate twigs as those of Schenk's ])lant, but the 

 internodes nre much shorter. The leaves when seen are always very 

 slightly prolonged above the joints, one being on each joint. But in some 

 twigs on many of the joints no leaves appear, as on the main stem in 1*1. 

 CXI, Fig. 2, and on many of the joints of PI. CXII, Fig. 5 ; when present 

 they are often barely visible. The joints are generally marked by strong- 

 constrictions, and many of them simply show a deeply sunken line, which 

 runs across the stem more or less obliquely, generally with a downward 

 bend towards the middle. It is evident that the ultimate twigs played the 

 part of leaves. Onl}- in the older and larger stems do we see any woody 

 axis, and this is alwa3's proportionally very small considering the diameter 

 of the twigs. The joints are placed ver}" clo.se together, ditTering in this 

 point markedly fi-om /'". noheiierjf/eri The epidermis is very dense and 

 strong, and it is owing to it that the twigs are often found well preserved 



The ultimate twigs were deciduous, and it is a rare thing to find any 

 •of them attached to stems. They usually aj)pear as detached fragments. 



