ORDER ACTINOIDEA. 41 



obliquely, and showing the radiating visceral lamellae, which connect 

 it with the sides of the visceral cavity. In figure 3b, only two oppo- 

 site lamella? are in view, while in figure 3c, which is an oblique 

 section, crossing the cavity below the stomach, the edges of several 

 of the intersected lamella? are exposed. In the last-mentioned figure, 

 the stomach is seen to terminate in a kind of disk, which is the mus- 

 cular arrangement for closing its lower extremity. The oblique 

 position of this disk is unnatural, and resulted from the section of 

 part of the lamella? and their consequent unequal contraction ; the 

 animal is drawn just as it was presented in the dissection. In 3b, the 

 upper extremity shows the tentacles as they are concealed in the con- 

 tracted animal. It thus appears that the visceral cavity is divided by 

 the lamella? into a series of compartments, as in the Actinia. A 

 second series of narrower lamella? lies between the larger, as is shown 

 in figure 3d. These narrower lamella?, however, are prolonged on the 

 under side of the disk to the stomach, so that in making the section 

 here referred to, the upper portion removed, presented below twice 

 as many radiating compartments as were seen in the part figured. 

 There is hence a close analogy with the Actinia, although the ani- 

 mals differ so strikingly in the relative sizes of the stomach and 

 visceral cavity. This resemblance is seen farther in the position of 

 the spermatic cords. 



33. Spermatic cords border the larger lamella?, and extend from 

 below the stomach nearly to the bottom of the visceral cavity. They 

 are convoluted throughout their length, as is shown in figures 3b, 3c, 

 and 3/1 It is remarkable, that in one of the specimens, the convolu- 

 tions are very few, and the cord stops far short of the bottom. This 

 fact may be accounted for on the principle that they are periodically 

 developed.* 



Spermatozoa were not observed in these cords, yet it is altogether 

 probable that on farther examination they will be detected, as in the 

 Actinia. Vibratile cilia were distinct on the cords, but were not seen 

 on the lamella? to which they were attached. 



The specimens examined contained no ovules. From analogy, we 

 should expect that in the proper season they would be found in 

 clusters, attached to the intermediate series of narrow lamella?. 



34.- Besides the spermatic cords, there is attached to the edge of 

 each larger lamella, immediately below the stomach, a pair of flat 



* The season when these observations were made was the month of August, 1840. 



11 



