174 JULY. 



diameter. Specimens, however, of this size are quite 

 common with us, nor would one of an inch and a half 

 be looked upon as at all exceeding the modest and pro- 

 per range of the species. 



It is of a pentagonal figure, with the margin a little 

 receding between the angles, but not so as to cause the 

 latter to form distinct arms. The body is flat below, 

 and plump and cushion-like above, of a yellowish olive 

 hue, with the very edge of a golden orange tint, while 

 a spot of the latter colour, a little out of the centre, 

 marks the situation of a remarkable organ called the 

 madreporiform tubercle, the proper use of which has not 

 as yet been satisfactorily determined. Just at the ex- 

 tremity of each angle, but a little below, is situated a 

 wart of rich crimson hue, which is supposed to be an 

 eye, being seated on a small ganglionic swelling of a 

 nerve that passes along the ray. It is true no crystal- 

 line lens has as yet been detected on the pigment dot, 

 either in this species or any other (for the specks are 

 found in the same position in all the proper Star-fishes), 

 but they are manifestly of the same character as similar 

 specks in Rotifera, and other humble animal forms, 

 which in some examples are connected with an indu- 

 bitable lens. It might seem at first as if the situation 

 of these eyes were not very favourable to vision ; but, in 

 truth, they command the ground just before and around 



