NOTES ON EMBRYOLOGY AND CLASSIFICATION. 



443 



Classes and Orders of the NEMATOPHORA. 



. Class. 



I. Hydro- 

 medusa . 



ii. podactinaria 



III. DlSCOMEDUS^ 



Order. 



1. Hydriformes 



2. Siphonophora 



i 



[_2>. Monopsea 

 Podactinaria 

 Discomedusse 



IV. 



Hydrocoral 



LIN^ 



c 



V. Anthozoa 



Petrosa . 

 Graptolitidse 



1. Hexactinise 



2. Tetractiniae 



3. Octactinige 

 pi. Eurystoma 



J 2. Saccata . 



Examples. 

 [Hydra, Tubulari a. 

 \8ertulana. 

 T Phi/sophora. 

 \Velella. 



{Geryonia. 

 Mginopsis. 

 Lucernaria. 

 f Rhizostoma. 

 \Aurelia. 

 r Stylaster. 

 '\_Millepora. 

 Graptolites. 



{Actinia, Oculina. 

 Antijoathes. 

 Cerianthus. 



(Alcyonium. 

 Tubipora. 

 Beroe. 

 [ Pleurohrachia. 

 \_Callianira. 

 Cestum. 

 Bolina. 



VI. Ctenophora 



3. Tseniata 

 [_4. Lobata 



Classes and Orders of the ECHINODERMA. 

 Branch a. AMBULACRATA. 



-o 1, f Holothuria. 



rneumonophora •{ nr y t 



^ {Molpaaia. 



1 ] Oncinolabes, 



Apneumona . < n u 

 ^ \_oynapta. 



Grade a. PAL^ECHINI. 



1. Melonitidse 



2. Eocidaridae 

 Grade b. 

 Branch 1. 



I. Holothuridea 



II. ECHINOIDEA . -^ 



1. Regularia 



2. Exocyclica 



Branch 2. 



1. Clypeastridee , 



2. Spatangidse . 



Melonites. 

 Eocidaris. 

 AUT ECHINI. 

 Desmosticha. 



{ Echinus. 

 Cidaris. 



r Galerites. 



< Echinoneus. 



( Dysaster. 

 Petalosticha. 



r Clypleaster. 

 "XEchinocyamus. 



\ Ananchytes. 

 \Poiirtalesia, 



