162 



species, showing a portion of the eye, the long genal spine, 

 and the granular surface 



Fig. 4 Dikelocephalus Tasmanicus. B. Eth., Jimr. A tail 

 exhibiting in an exceedingly fine manner the characters of the 

 species, including the long tail spines. 



Fig. 5. Asaphus, sp. h. Larger portion of a pygidium or 

 tail, with a wide limb, or border, delicately striated. 



Fig. 6. Asaphus, sp. a. A similar, but smaller and much 

 more oval tail. 

 Fig. 7. Labrum. 



Fio". 8. Glabella and portion of the fixed cheeks of a Trilo- 

 bite, which would perhaps fall within Hall's definition of 

 Conocephalites. 



Fig. 9. Side view of the same. 



Fig. 10. Another form nearly allied to Fig. 8, but having a 

 more pear-shaped glabella, and wider frontal margin. ^ 



Fig. 11. Another glabella, of a squarer form than in either 

 of the preceding, and with only one pit-like furrow on each 

 side. 



Fig. 12. Fragmentary head-shield, with an almost quadrate 

 glabella, and no visible furrows. 



Plate II. 

 Fig. 1. Pentamerus Tasmaniensis, R. Etheridge, Junr. 

 Internal cast of the dorsal valve, showing the cavities of the 

 two septa, enclosing between them a portion of the V-shaped 

 or fifth chamber. 



Fig. 2. Spirifer sp., dorsal valve, perhaps, of Fig. 16. 

 Fig. 3. Pentamerus Tasmaniensis, an internal cast of the 

 ventral valve, exhibiting the cavity left by the large septum. 

 Fig. 4. Side view of the same specimen, with the deflected 

 sides and front of the shell. 



Fig. 5. Another dorsal valve of the same species. 

 Fig. 6. Portion of another ventral valve, showing the septal 

 character and muscular scars. 



Fig. 7. Portion of a slab, with portions of three individuals, 

 and part of another, in which the fifth or V-shaped chamber 

 is exposed by fracture. 



Fig. 8. The fractured portion removed from No. 7. 

 Fig. 9. Portion of a slab with (a & c) Spirifer, resembling 

 8. plicatella, Linn. (6), another Spirifer, not unlike S. crispa, 

 His. or S. elevata. Dalman. x 2. 



Fig. 10. Portion of another form of Spirifer (?) or perhaps 

 an Atrypa. 



Fig. 11. Fragment of a shell, with the appearance of a 

 Strophomena. x 2. 



Fig. 12. Cast of a small Tentaculites. x 3. 

 Fig. 13. Small Univalve, in all probability an Ophikta, from 

 a wax cast. 



