‘ PORCUPINE ’ DEEP-SEA DREDGING-EXPEDITIONS. 
751 
C. fenestrota , Neolaw/pas rostellata, Pourtalesia Jeffreys i, and P. ffiyale) are forms 
which have been for the first time brought to light during the late deep-sea dredging- 
operations, whether on this or on the other side of the Atlantic : there seems little 
doubt that these must be referred to the abyssal fauna, upon whose confines we are 
only now beginning to encroach. Three of the most remarkable generic forms, Cal- 
veria, Neolampas , and Pourtalesia , have been described by Prof. Alexander Agassiz 
among the results of the deep-dredging operations of Count Pourtales in the Strait of 
Florida, showing a wide lateral distribution ; and even a deeper interest attaches to the 
fact that while one family type, the Echinothurida:, has been hitherto known only 
in a fossil state, the entire group find nearer allies in the extinct faunae of the Chalk, or 
of the earlier Tertiaries, than in that of the present day. 
Description of the Plates. 
PLATE LIX. 
Ci daris papillata. 
Fig. 1. Test of a full-sized specimen, showing the arrangement of the apical disk. 
Natural size. 
Fig. 2. Portion of the test, showing the arrangement of the scales of the buccal mem- 
brane. x 2. 
Fig. 3. Radials from the region of the ambitus. Natural size, and fig. 3 a X 2. 
Fig. 4. Small spine from the ambulacral area, x 20. 
Fig. 5. One of the inflated pedicellarise from the apical disk. X 25. 
Fig. 6. Tridactyle pedicellaria from the edge of the pore-area. X 25. 
Fig. 7. Tridactyle pedicellarise from the miliary area of the test. 
Fig. 8. One of the ambulacral tube feet, showing the calcareous spicules of the wall 
and the rosette of the sucker, x 50. 
Fig. 9. Spicules from the ambulacral tube feet. X 100. 
Fig. 10. Portion of the mesenteric membrane, showing the fenestrated supporting 
plates. X 15. 
Fig. 11. The wall of the intestine, showing the calcareous plates. 
Fig. 12. One of the ultimate branches of the ovary, showing the fenestrated plates. 
X 25. 
Fig. 13. Plates from the wall of the ovary. X 50. 
Porocidaris purpurata. 
Fig. 14. Didactyle pedicellaria from the edge of the pore-area. X 50. 
Fig. 15. Fenestrated plates in the wall of the intestine. 
5 i 
MDCCCLXXIV. 
