INVEKTEBRATE ANIMALS. 17 



Where VERMES is adopted as a main division, 

 the Polyzoa are generally included in it. 



A monogra-ph of the class Polyzoa, coiiibining the fossil icith the 

 recent species, after the admirable method of Milne Edwakds in 

 his Histoire Naturelle des Coralliaires, may be regarded as an 

 achievement worthy the ambition of any Naturalist. Taking 

 into consideration the exquisite beastly of the species, their wide 

 distribution in time and space, their convenient size, and the 

 interesting questions connected with their structure and habits, no 

 other unoccupied Biological field seems to present equal attraction. 

 Valuable assistance, in identifying the species, and by the contribu- 

 tion of rare and beautiful specimens in this class, has been given by 

 Miss Horatia Gatty. 



The three groups here assigned to this class are based upon characters 

 by no means satisfactory, but it has been found convenient to retain 

 them. The more scientific distinctions are illustrated by coloured 

 drawings in the upper compartment. 



Group 49. — Genus RETEPORA (Lamarck) ; rete, a net ; 

 and allies. Polyzoarium chiefly calcareous and rigid. 

 II Examples of Tuhulipora, Cellepora, Idmonea, 

 Hornera, &c., including some very beautiful 

 Retepores and other Polyzoa from the Atlantic 

 Cable. Oldhamia, from the Cambrian rocks, 

 may probably be a plant. 

 Group 50. — Genus FLUSTRA (Linnaeus). Saxon Flustrian, 

 to weave ; and allies. Polyzoarium chiefly horny, 

 foliaceous or explanate. 



^Examples of Lepralia, Carhasca, Memhranipora, 

 Electra, &c. Observe how closely Ainathia 

 spiralis (Lamouroux), from Australia, resem- 

 bles in form Archimedipora Arcliimedea 

 (Lesuer) ; a fossil from the Carboniferous 

 Limestone, Kentucky. A delicate cup-shaped 

 Flustra on Catenicella. 



Group 51.— Genus CATENICELLA (Blainville) ; catena, 



