The Graptolites of Lance field Beds. 165 



All the specimens come from a small quarry a few hundred 

 yards to the north of the now deserted Mount William railway 

 station. There ai-e at least three distinct bands containing 

 fossils, but if any palaeontological differences exist between them 

 they are very slight, and a collation of the species associated on 

 a large number of slabs has yielded no definite results. This 

 point must be insisted on, as otherwise, the association of the 

 forms here dealt with, would, by European analogy, induce the 

 opinion that several very distinct horizons were confused, which 

 is certainly not the case. 



Bpyograptus, Lapworth, 1880. 



Bryograptus victoriae, n.sp. 



(PI. XVII., Figs. 1, 2). 



Branches diverging at first at about 50°, curving towards one 

 another and again dividing at about 70" or 80°, forming a bell- 

 shaped hydrosome. Sicula with a prolonged virgula of about 



2 mm. in length. Thecae straight-sided, apertural margin at 

 right angles to the branch, outer margin at an angle of about 

 10° or 12°; about 10 in 10 mm. Breadth of branches about 

 0'5 mm. 



There is no evidence of overlapping of the thecae in any of the 

 specimens I have seen. 



The fine thread extending from the pointed end of the sicula 

 is morphologically a virgula, and no useful purpose is served by 

 applying a different name to it. Its presence has of course long 

 been recognised in such forms as Didymograptus caduceus, 

 though its true nature was long misunderstood. 



Bryograptus clarki, n.sp. 



(PI. XVII., Figs. 3, 4). 



Branches straight and inclined at an angle of about 135°, 

 0-5 mm. broad, giving off branches on their inner side near the 

 sicula. These four branches again branch at a little more than 



3 mm. from their point of origin. Sicula with a short virgula. 

 Thecae about 10 in 10 mm., straight sided; apertural margin 

 inclined at about 100° to the axis of the branch; outer margin 



