rno TRANS. ST. LOUIS ACAD. SCIENCE. 



The specimens obtained are not entire. The branches are often 

 widely separated, and are sometimes long and flexuous, extend- 

 ing for several centimetres in length. It sometimes happens that 

 we obtain a long stipe which may be either a portion of the struc- 

 ture below the branches or a portion of a separate branch. 



Formation and Locality. — This species occurs in the Niagara 

 dolomites at Hamilton, Ontario. 



Thamnograptus(?) multiformis, nov. sp. 



Plate 6. Figs. 2 & 3. 



Stipes simple, flexuous, and strong, usually divided into two 

 (sometimes three) branches of equal thickness. From both the 

 undivided and divided stipe a few short irregular branches origi- 

 nate at long unequal distances apart ; and these may or may not 

 end in two free points. The texture is corneous and black, with 

 the surfaces somewhat striated and impressed with a medial line 

 (indicating a central axis?). In occasional specimens of the same 

 mode of branching, short spine-like processes, from one-half to 

 one millimetre long and half a millimetre apart, probably indi- 

 cate the position of the cellules on both sides of the branches. 



There is considerable variation in the size of these organisms. 

 The larger specimens are four or five centimeters long, and the 

 stipes are usually about one millimetre thick ; however, some of 

 the specimens, that I have referred here, have not more than half 

 that size. In the larger specimens the branches are usually about 

 half a centimetre apart. 



In the rocks of the Niagara formation numerous fragments of 

 organism of the Graptolite Family occur. Vast numbers, con- 

 sisting of thick broken stipes, often flexuous, with one or two 

 branches, or those with dichotomous terminations, are found, and 

 cannot be referred to any species described. Yet they so closely 

 resemble the better specimens of this species that I have placed 

 them here, although a further study might separate some of them 

 from this species. 



Formation s;;^ Z^^r^/Z/y. — Fragments of this species occur some- 

 what abundantly in the Niagara dolomitic rocks at Hamilton, 

 Ontario. 



