ROSY FEATHER-STAR. 15 



specimens of Peniacrinm Europaus preserved in spiriK 

 also some very young Comatula. In one of Mr. Thomp- 

 son's specimens of the latter, 1 found the basal disk con- 

 centrically ribbed, and presenting- traces of a central per- 

 foration. Its pentangular form would lead us to suppose 

 that the column of the young animal is of the same shape. 

 The column of the Pmtacrinus Europaus examined Mas 

 very long- compared with the body, and composed of 

 eighteen joints. Under the microscope it appeared of a 

 granular texture. When compressed between plates of 

 glass and highly magnified, the substance of the column 

 and body presented a beautiful reticulated appearance, in 

 consequence of the separation of the plates of calcareous 

 matter with which it was studded. These plates were 

 mostly pentagonal. They are themselves composed of 

 little calcareous particles, each of which also appears to 

 be pentangular ; but they adhere more firmly together 

 than the plates do to one another. The same peculiar 

 regular granular structure is seen in the calcareous sub- 

 stance of other Echinodermata, especially when the animal 

 is young ; and such a structure is very favourable to the 

 spheroidal growth of these creatures. 



The adult Comatula frequents both deep and shallow 

 water. In deep water we find them full grown ; and when 

 dredging in such a situation I have never seen a small one. 

 In the region of Laminariffi they abound in several lo- 

 calities, and there are found of all sizes, in company with 

 the stalked form or Phytocrinus. Probably they frequent 

 those forests of sea- weeds for breeding purposes at certain 

 seasons, and retire to the deep sea at other times. We 

 are told by Mr. J. V. Thompson that Comatula swims 

 like a Medusa. " In swimming, 1 ' he says, " the move- 

 ments of the arms of the Comatula exactly resemble the 



