ZOOPHYTA BRITANNICA. 



ORDER II. 

 Z. ASTEROIDA. 



Character. 



Polypes compound, the mouth encircled icith 8 pectinate tenta- 

 cida ; stomach membranous ivith dependant vasculiform appen- 

 dages ; intestine ; anus ; reproductive gemmules produced in- 

 teriorly. Polype-mass variable in form, free or permanent- 

 ly attached, carnose, generally strengthened with a horny or cal- 

 careous axis enveloped ivith the gelatinous or creto-gelatinous 

 crust in which the polype-cells are immersed, and which open 

 on the surface in a starred fashion with 8 rays. 



Observations. 

 On a cursory view the Polypidoms of the three families em- 

 braced in this order appear very dissimilar, and accordingly, by 

 many recent authors, they have been scattered over the class, 

 and placed widely asunder. The affinity between them, how- 

 ever, is generally acknowledged, and had been distinctly per- 

 ceived by some of the earliest zoophytologists. Thus Bohadsch 

 found so much in common between the typical Pennatulae and 

 a species of Alcyonium, that he has not hesitated to describe 

 them as members of the same genus ; and although the more 

 systematic character of Pallas prevented him falling into this 

 error, — if error it can indeed be called, — he did not the less 

 recognize the relationship between the genera or families.* Pal- 



" " Pennatulae Alcyoniis specierum gradatione ita propinquse sunt et tamen 

 simul structura, habitu, vitseque sensitivse gi-adu discrepant, ut exempliini majoris 

 siraul affinitatis et discordantise inter duo genera in rerum natura vix dari exis- 

 timem. Certo respectu Pennatulae ad Alcyonia sunt, quod Hydraead Sertularias." 

 Elench. p. 362 — In' relation to this paragraph consult also p. 370, 343, 162, 

 191:— and Misc. Zool. p. 177. 



