344 Br. H. Woodward — New TriloUtes from S. Australia. 



a curved line towards the eye, then bends towards the posterior angle, 

 and cuts the margin obliquely. 



Mr. Robert Etheridge, jun., in a paper published in the Proceed- 

 ings of the Eoyal Society of Tasmania (read 13th June, 1882, p. 152, 

 et seq.), discusses the characters of this genus most fully. 



I have compared Tig. 2 with numerous species of these primordial 

 forms, all in a more or les^ fragmentary condition, and whilst 

 admitting that probably Conocephalites might with propriety be sub- 

 divided into two or more genera, at present sufficiently-well-preserved 

 specimens are wanting to enable one to break it up. 



In the specimen from Yorke's Peninsula, the sides of the glabella 

 are tolerably parallel, broadly rounded in front, with two indistinct 

 transverse furrows on each side ; the neck furrow is broad and deep ; 

 the neck-lobe is rather broad ; the fixed cheek remains on the right 

 side ; the facial suture is somewhat oblique, commencing in the 

 margin near the anterior angle of the glabella, and bending outwards 

 to the eye, which is placed on the anterior half of the head ; oblique 

 striae can be seen on the cheek in advance of the eye which spread 

 from it to the anterior border of the glabella ; the eye was probably 

 long and narrow, but is too much injured to be described ; the surface 

 of the glabella and fixed cheek are finely punctate (see PI. XI. Fig. 2b). 



Length of glabella including neck-lobe 17mm., breadth 10mm. 



There is a general resemblance between this South Australian 

 Conocephalites and many of the species figured on plates vii. and viii. 

 of the " Sixteenth Eeport of the Regents of the University of the 

 State of New York, on the Condition of the State Cabinet of Natural 

 History," Albany Contributions to Palaeontology (1863, 8vo. pp. 

 147-168). Compare our figure with that of the Potsdam Sandstone 

 specimens figured on plate vii. op. cit. figs. 10, 24, 30, 31, 36, 37, 

 and plate viii. figs. 5, 8, etc. ; but it is quite distinct specifically from 

 any and all of these. It is also distinct from those figured and 

 described by Mr. R. Etheridge, jun., from the Lower Silurian of the 

 Mersey River District, Tasmania. 



This specimen, for the sake of convenience, might bear the trivial 

 name of C. Australis. 



These Trilobites are clearly of Lower Silurian age, being equivalent 

 to the Swedish, Bohemian, Tasmanian, and North American beds with 

 similar fossils. 



EXPLANATION OF PLATE XI. 



Fig. 1. ^schna Flindersiensis, H. "Woodw. Cretaceous ; Flinders Eiver, 



North Queensland. 

 J, 2. Conocephalites Australis, H. Woodw. Cambrian, or Lower Silurian, 



Yorke's Peninsula, South Australia. 

 „ 3. Dolichometopus Tatei, H. "Woodw. ditto ditto. 



,, 4. Jiatica, STp. (cast). Cretaceous? South Australia. 

 ,, 5. Gervillia ani/mta, Hudl. Two double valves. 



,, 6a, h. Modiola linguloides, Hudl. Left valve and side view of both valves of 



same specimen. — N.B. The outline of the 



larger specimen is traced outside. 

 ,, la, b. Cyprina ? species. Left valve and side view of same specimen. 

 „ 8a, b. Cytherea Woodwardiana, Hudl. Eight valve and side view of same. 

 ,, 8c. lb. lb. Internal cast showing pallial sinus. 



,, 9. Myacites australis, Hudl. 



,, 10. Avieula orbicularis, Hudl. 



