CLASSIFICATIONS OF ZOOPHYTES. 71 



IV. NUDA. 



Polypi naked, the mouth with marginal tentacula. 

 Coryna. 

 Hydra. 



Latreille's method may next be noticed. He, following La- 

 marck, divides the animal kingdom into three primary sections, 

 the last of which is denominated Acephala, which, with various 

 other classes, includes all the Zoophyta. The Actinia and Lu- 

 cernaria constitute a distinct class — Helianthoida — which is 

 placed between the sea-stars (Echinodermata), and sea-jellies, 

 (Acalepha), being superior to the latter and to zoophytes by 

 their organization, in which Spix had detected a nervous system. 

 The Polypes follow the sea-jelhes, and are subdivided thus : 



Order I. Brachiostoma. 

 Month encircled with tentacula, often relractile. 

 Family I. Calamides. Pennatula, Virgularia, &c. 



• II. Alcvonea. Lobularia, Alcyonium, S:c. 



III. Alveolaria. This family is portioned into tribes. 



1. LamelUfera — the P. lamelliferes of Lamarck. 



2. Foraminosa — the P. foramines of Lamarck. 



3. Corticifera — the P. corticiferes of Lamarck, with 



the genera Penicillus and Flabellaria. 



4. Reticularia — the P. a resean of Lamarck. 



5. Vaginiformia — the P. vaginiformes of Lamarck. 



6. Spongites — the sea and fluviatile sponges. 

 IV. Limnopolypi. 1. Tentacula i-etractile ; a sheath — 



Plumatella, Cristatella, Difflugia. 2. Tenta- 

 cula non-retractile ; no sheath — Pedicellaria, 

 Coryne, Hydra. 



Order II. Trichostoma. 

 No tentacula at the mouth, which are replaced by rotatory organs or 



cilice. 

 Family I. Cancriformia — Brachionus, Follicularia, Tul)icolaria. 



II. Campanulata — Vorticella, Urceolaria, Furcnlaria. 



HI. Caudata — Vaginicola, Tricocercus, Ratulus. 



Not having access to the original works, I pass over in silence 

 the methods of Oken, Schweigger, and Van der Hoven, the 



