Hall : Victorian Graptolites. 2 1 



almost inaccessible district, and results of interest may be ex- 

 pected, especially as the presence of Heathcotian is asserted. 



The recent publication by the Palaeontologioal Society of the 

 fourth part of Miss Elies' and Miss Wood's Monograph of 

 British Graptolites, which deals with the Dicranograptidae, ren- 

 ders it possible at last for useful comparisons of our Australian 

 species to be made with those of Europe. The small size and 

 complicated form of the thecae of this group, together with their 

 frequent imperfect condition of preservation, owing to their 

 •delicate structure, and their habit of being embedded at all 

 angles in the bedding plane, make their elucidation one of con- 

 siderable difficulty. The older descriptions and figures Avere 

 inadequate, but the revision of the authors mentioned makes 

 easy much that was formerly unintelligible. 



The specimens which Mr. Thiele has been kind enough to 

 allow me to examine I have identified as follows: — 



Diplograptiis thielei, ii. sp. 

 Climacograptus wellingtonensis, n. sp. 

 CI. bicornis, J. Hall. . 

 Cryptograptus tricornis, Carruthers. 

 Lasiograptus, sp. 



Dicellograptus elegans, Carruthers. 

 Dicranograptiis nicholsoui, Hopkinson. 

 Dicr. hians, n. sp. 



These are clearly of Upper Ordovician age. The descriptions 

 of the previously-naaned species have been drawn up from 

 specimens in the present collection, no character being dealt 

 with which cannot be seen in them. 



Diplogpaptus thielei, n. sp. (PI. VI., Fig. 1). 



Hydrosome rather broad, the edges gradually diverging from 

 the sicular end. At about 8 or 10 mm. from the sicula, they 

 become parallel, and so continue to the truncate extremity. 

 Sioula nearly one mm. broad at its apertiu-e and one and a half 

 mm. long. Thecae about 4-^- times as long as broad, overlapping 

 § their length. Outer wall of the earlier thecae gently sig- 

 moidally cuiwed. In the later ones it is straight. The earlier 

 thecae have spines about 0.5 mm. long ; these decrease in size, 

 and ultimately vanish towards the anti-sicular end. 



