EXPLANATION OF PLATES. 



PLf\TE 29. PAGR 



PENTREMITES GODONI, De France. Rowley. >i9 



FIGS. 1-2, — Basal and side views of a six-rayed speci- 

 men, figure 2 showing the size and shape 

 of the extra radial. 



FIGS., 3-i. — Summit and side views of a specimen with 

 a pyramid covering the ventral openings 

 and a low arching integument' extending 

 a short distance downward over each am- 

 bulacrum. 



FIGS. 7-8. — Summit and side views of a specimen 

 with but four ambulacral fields, the fifth 

 radial being narrow and indistinctly 

 grooved along the middle. A strong 

 rounded fold extends down the middle of 

 one of the four ambulacral areas. 



PENTREMITES PYRIFORMIS, Say, Rowley. 89 



FIG . 12. — Side view of a specimen that has been in- 

 jured in life and repaired by the secretion 

 of stony material along the lines of frac- 

 ture or crushing. 



FIGS. 21-22-23. — Side and basal views of a six-rayed 

 specimen, figure 22 showing the extra 

 non-ambulaeral bearing radial plate and 

 figure 23, the irregularity in outline 

 due to the crowding of two ambulacra. 



PENTREMITES KONINCKANUS, HaU, Rowley. 90 



FIGS. 5—6. — Side and summit views of a specimen 



showing the summit pyramid, x 2. 

 FIGS . 9, lOa-11. — Basal, summit and side views of a 



tetraradiate specimen, the central part of 



one amb'ilacrai area being occupied by a 



strong fold, x 2. ' 

 FIG. 10. — Is a faulty drawing corrected in 10a, x 2. 

 FIGS . 13-14. — Side and basal views of a symmetrical 



four-rayed specimen, x 2. 



PENTREMITES CONOIDEUS, Hall, Rowley. 87 



FIGS. 29-30. — Side views of two different specimens 

 to show outline. 



FIG. 37. — Interior of a specimen, broken across, 

 showing the hydrospire folds, x 2. 



FIG. 3?. — Similar view of another specimen, show- 

 ing one hydrospire area. 



FIG. 39. — An interior view of a specimen siiowing the 

 anal opening, mouth and broken hydro- 

 spire tubes, X 2. 



