A SYNOPSIS OF ANIMAL CLASSIFICATION. 



Sub-type I. CNIDARIA. 



Sessile forms known as polyps, and free-swimming ones known 

 as medusa, often occurring as various generations of the same species. 

 Tentacles are almost universally present, and these and other exposed 

 parts are armed with cnidoblasts, or "nettle-cells." 



Class I. HYDROZOA Animals based upon the plan of a 



simple polyp, the Hydrula. 



Order i. AuTHYDRiE Polyps which produce other polyps 



without an intervening medusa- 

 generation. 

 Sub-order I. Hydrida Simple, fresh-water polyps. In- 

 dividuals solitary, not forming col- 

 onies. Reproduce asexually in 

 summer and sexually at the ap- 

 proach of winter. x Hydra. 

 Sub-order 2. HydrocorallincB.'YTO^\C'i\. marine forms in poly- 

 morphic colonies, producing a sort 

 of coral. X Millipora. 



Order 2. Hydro-medusae Polyps of the hydrula form, and 



small medusae with velum; these 

 forms usually appear as alternate 

 generations of the same animal. 

 Sub-order i. Gymnoblasiea- 



anthomedusce Sessile colonies of polyps with re- 

 productive medusae, free or re- 

 duced. The polyps are naked, i.e., 

 not protected by the perisarc. 

 The medusae possess ocelli and 

 genital organs in the manubrium. 

 X Pennaria (with reduced medusae). 

 Podocoryne (with free medusa, the 

 form called Dysmorphosa). 

 Sub-order 2. Calyptohlasiea- 



leptomedusce Sessile colonies of polyps with re- 

 productive medusae, free or re- 



