1854.] 



NEW GENERA AND SPECIES OF CYSTIDEA. 



Fig. 6. Amy •gdalocy 'stiles tenuhlriaius. 



Fig. 9. 



271 



Fig. i. A specimen with a part of the arm, ovarian aperture, and four 

 joints of the column. Surface character of the plates not tcell preserved. 



Fig. 5. A fragment from the same slab, showing the markings of the 

 plates and three of the teniacula. 



Fig. 6. A single plate. 



In this species a low rounded tubercle is situated in the centre 

 of each plate, from which ridges radiate to the angles. These 

 ridges are scarcely elevated above the surface, where they leave the 

 border of the tubercle in the centre of the plate, but increase in 

 width and height as they depart from it They are sharp above, 

 and attain their greatest elevation at the angle of the plate. The 

 ovarian aperture is situated close to the arm near the summit, and 

 appeal's to be formed of six triangular plates. The short fragment 

 of the column which remains is composed of four joints about the 

 sixteenth of an inch in thickness. The fragment, Fig. 5, shows- 

 the form of the plates and three of the tentacula attached to the 

 arm. The remainder of the specimen is concealed. 



Amy gdalocy stites radiatus. 



Fig. 7. 



Fig. 8. 



Fig. 7. Pari of the body and column of a specimen. 

 Fig. 8. A plate enlarged. 



This specimen consists of the lower part of the cup, and about 

 one inch in length of the column of a Cystidean, which will probably 

 be found to belong to the same genus as the last The plates are 

 somewhat convex exteriorly ,and ornamented with strong rays,\vhich 

 extend from the centre to the angles. At the base a large six-sided 

 pelvic plate is seen resting on the column. From the width of 

 this plate in proportion to the size of the column, it appears that 

 the pelvis is formed of three plates. The column is round and 

 smooth. The impression upon the stone shows that this indivi- 

 dual was of the size indicated by the dotted line in the figure. 



Fig. 9. A specimen separated from the matrix, but crushed quite fiat, and 

 broken into three pieces, a — the ovarian, aperture. 



Of this species I have only the single specimen figured. The 

 plates are elevated and smooth in the centre. A low rounded 

 ridge proceeds from the smooth space to each angle. Between 

 these ridges fine strise cross from one plate to the other, at right 

 angles to the sutures. The pelvis consists of three broad penta- 

 gonal plates. The column is round, and formed of very thin 

 plates. The ovarian aperture is nearly on the top of the summit 

 Neither arms nor mouth have been observed. The specimen is 

 separated from the matrix, but crushed quite flat, and broken 

 across in two places. 



These three last described species appear all to belong to a 

 genus different from Comarocijstites, and I have therefore dis- 

 posed of them as above, provisionally. When more becomes 

 known about them, it may be necessary to make another arrange- 

 ment 



Agelacrimies. 

 Fig. 10. Fig. 11. 



5* 



Fig. 12. 



r 



Fig. 10. Partly restored figure of Agelacrinite from the Trenton Umetone, 

 -By town, a — supposed ovarian aperture. 



Fig. 11. Plates surrounding the mouth, under side. These plates hare all 

 an elevated border on the side next the mouth, below, caused by the 

 bending down of the plate, as seen in Fig. 12. 



Fig. 12. Vertical section through the mouth. 



This genus has been long known in Europe by a single speci- 

 men discovered about thirty years ago at the Chaudiere Falls in 



