SEA-ANEMONES AND THEIR ALLIES. 81 



Sub-class II. SCYPHOMEDUS.E. Jelly-fish with subgenital pits and 

 no velum or veil. 



Order I. DISCOMEDUSJE. Active forms with complicated life-history. 

 Four horseshoe-shaped genital organs . . . Aurelia. 



Order II. LTJCENARIJE. Sessile forms . . Ealidystus. 



Class III. CTENOPHORA. Free living forms with eight rows of 

 plates. 



Two tentacles and small mouth . . . Pleurobrachia. 



No tentacles and wide mouth . . Beroe. 



SUMMARY CLASSIFICATION OF CCELENTERA, OR SEA-NETTLES. 



Class I. HYDROZOA (Chap. II.). 



(a) Gymnoblastea, polypes without 

 protective sheath, e.g. Clava and 

 ^ -, TT -, j other common zoophytes. 



A. Order Hydromedus* j (i) C alyptoblastea, polypes placed in 

 cups, e.g. Obelia and other com- 

 mon sea-firs. 



B. Order Siphonophora . 



Class II. SCYPHOZOA (Chap. III.). 



A. Sub-class ANTHOZOA. 



1. Order Zoantharia sea-anemones and corals. 



2. Order Alcyonaria "dead men's fingers," sea-pens, etc. 



B. Sub-class SCYPHOMEDUS^:. 



Various orders, including the large jelly-fish and Haliclystus. 

 Class III. CTENOPHORA. Free-swimming forms like the "sea- 

 gooseberries" (Beroe), etc. 



NOTE ON DISTRIBUTION. 



The sea-anemones described in this chapter have been those of the 

 East Coast, which is poorer in species than any other part of our area. 

 It is not possible to name all the common anemones of the South and 

 West, but a few notes may be given. In most places on the West the 

 beautiful Anthea cereus, an anemone with smooth column and non- 

 retractile tentacles which occurs in a brown and a green variety, is 

 common. It is especially common on the coasts of Devon ; north 

 of Devonshire, so far as my experience goes, the brown variety is 

 commoner than the green, which is much the handsomer. Again, 

 while at Alnmouth, St. Andrews, and on the shores of the Firth of 

 Forth, Sagartia troglodytes is excessively common, it is probably less 

 common on the South and West is certainly rendered less con- 

 spicuous by the occurrence of many other somewhat similar species. 

 At Mill port, for instance, Sagartia miniata, which has the outermost 

 row of tentacles with a scarlet core, is one of the commonest anemones 

 of the pools. Another species, Sagartia bellis, or the daisy anemone, 

 is very common on the coasts of Devon and Cornwall. 

 G 



