PLATE 28. 



Fig. 1. 123. 1. PoTEniocKiNus alternatus. (Pag. 83.) 



1 a. A specimen upon the weathered surface of the limestone, showing imperfectly the structure and arrange- 

 ment of tlie plates, with the tentacula and a portion of the column below. 



1 b. Shows the arrangement of the plates around the column, and the attachment of the fingers to the upper 

 part of the brachial plate. 



1 c. A brachial plate separated. 1 d. A costal plate separated. 1 e. A pelvic plate. 



1 /. A portion of the column of this species, showing the alternating width and rounded edges of the plates. 



Fig. 2. 124. 2. PoTEKIOCRINTTS GRACILIS. (P^g. 84.) 



2 a. A specimeh of the natural size, broken off just below the last joint of the column, which adheres closely 



to the pelvis. The tentacula are broken off above, before reaching their termination. 

 '2 b. The same enlarged, showin*:; more clearly the arrangement of the plates, arid the situation of the inter- 

 costal plate. 



E. Pelvis. 



F. Costal plates. 



J. Irregular intercostal plate. 

 H. Scapular plate. 

 2 c. The body of another specimen, vyith a few of the last joints of the column attached. 



2 d. The same enlarged, showing the intercostal plate and the structure of the column. 



Fig. 3. 125. 1. ScYPHocRiNus HETEROcosTALis. (Pag. 85.) 



3 a. A specimen (natural size), with the fingers and column broken oflT; tlie form otherwise well preserved. 



3 b. The structure and arrangement of the plates, the letters indicating the parts as explained in the previous 



figures. The plates are slightly enlarged beyond their natural size. 

 3 c. The base of the specimen magnified, to show the fimbriated plate adhering to the base of the pelvis. 

 3 d. Lateral view of a smaller specimen of the same species, with portions of the fingers remaining. 



3 e. The same, showing the base, with a fragment of the column broken off and lying at the side. 

 3f. A portion of this column magnified, to show the character of the plates. 



Fig. 4. 378. 2. Schizockinus steiatus. (Pag- 316.) 



'I a. The body of this species, with a small part of the cohimn attached. 

 1 h. A portion of the column enlarged. 



4 (*. An eidarged figure, showing the structtu'e and arrangement of the plates. 



