Anatomy of the Ventriculites of ManteL S3S 



designated it an Astroite ; he has reversed the natural position 

 of the original. 



Parkinson in his great work on Oryctology, brought 

 together all that had been published deserving of notice, relative 

 to these bodies ; and gave an elaborate account of them, ac- 

 companied with some investigations of his own ; from which 

 he was led to conclude they were not ^Icyonia, nor Sponges, 

 but that there required a new genus to be formed for their 

 reception. Since that period he has published Outlines of 

 Oryctology^ in which really multum in parvo work * he has 

 divided the fossils before known under the common term 

 ^cyonia into four distinct genera, viz. Spongites, Syphonites, 

 Mantellites f, and Alcyonites. 



But to Mantel we are indebted for the most scientific ex- 

 amination of, and rational conclusions on, the anatomy and 

 physiology of these organic remains. His observations were 

 first published in the eleventh Volume of the Trans. Linnean 

 Society, and afterwards more fully in a very interesting and 

 excellent work on the fossils of the South Downs. He has 

 there shown they were the remains of a zoophyte, the general 

 form of which was that " of a hollow inverted cone, having 

 numerous ramose fibres proceeding from the base, by which 

 it was attached to other bodies ; and internally it possessed 

 a surface covered with the apertures of numerous tubuli, m 

 all probability the openings of absorbent vessels, by which 

 its nutrition was effected ; . . . . that the substance of the 

 original must have been soft and elastic, susceptible of spon- 

 taneous expansion and contraction." He further observes, 

 " whatever may have been the nature of its aliment, it seems 

 probable that it underwent a certain degree of digestion and 

 assimilation before it was fitted for its support, and that the 

 nutritious particles were taken up by the openings so nu- 

 merously distributed on the inner surface of the ventricular 

 cavity." He was also disposed to believe that, " like the 

 AXcyhma, and Actiniae, they were permanently fixed to the 

 rock upon which they grew." Mr. Mantel gave them the ap- 

 propriate name, Ventriculite, and formed a genus for their 

 reception, possessing the following characteristics : — 



General Character — Body inversely conical, concave, ca- 

 pable of contraction and expansion ; original substance spon- 



* Outlines of Oryctology, &c. by James Parkinson, 1822, from p. 50. to 

 p. 62. 



f The Ventriculites of Mantel. I adopt Mr. Mantel's very appropriate 

 name for this genus of zoophytes, in preference to the complimentary one 

 given by Mr. Parkinson, principally for its conveying an idea of a very cha- 

 racteristic part of it ; yet partly because I consider this fashion in the choicQ 

 of names should be confined to the trivial or specific name. 



z 3 



