EXPLAXATIOXS OF PLATES, PPP. 37 



Fig-. 7. A terminal joint of one of the large swimming feet, 

 showing the serrated margin enlarged to two diam- 

 eters. The terminal plate is restored in outline. 



Fig. 8. A separated metastoma, showing the form and or- 

 namentation enlarged to two diameters. 



EUKYPTERUS POTENS, n. Sp. 



Fig. 9. A portion of a large ectognath. 



Fig. 10. A large fragment of indeterminate relations, possi- 

 bly a portion of a large ectognath. A colony of 

 Splrorhis is represented on the upper right hand 

 angle attached to some underlying substance, prob- 

 ably of a plant. 



PLATE V. 



EUKYPTERUS MaNSFIELDI. 



Page 32. 



Fig. 1. An imperfect specimen, preserving the segments of 

 the abdomen, the telson and the large swimming 

 appendages. 



Fig. 2. A smaller individual, nearly entire, showing on the 

 last abdominal segments what appear to be the ar- 

 ticulating surfaces of the segments, or folds pro- 

 duced by the pressing together of the ujiper and 

 under surfaces. 



Fig. 3. A large spt-cimen, showing the entire form. Four 

 of the palpi are preserved, and a portion of the 

 right swimming foot has been uncovered under the 

 abdonnnal segments. The specimen being too long 

 for the plate, the extremity of the telson is repre- 

 sented as broken and its continuation given above. 

 The spinous pro(;esses at the post-lateral angles of 

 the segments are \vell-i)reserved, and sliow a dis- 

 tinctive ornamentation. 



Fig. 4. An enlai'geuient, to six fliauH'ters, of the edge of a 

 portion of the left lateral niMriiin of tlie segments, 

 showing the striated edge and ilir n.niow, triangu- 

 lar scales uilli iiiiiiiitc interniedjnte scales. 



