20 Coelenterata. 



6. Ctenophora. 



Hierher Mortensen, ferner Bigelow( 2 ). Uber die Entwickelung s. oben p 10 

 Yatsu, das Leuchten von Mnemiopsis unten Arthropoda p 55 Howard. 



7. Anthozoa (incl. Hydrocorallia). 



A. Zoantharia. 



For Actiniaria see McMurrichl 1 , 2 ), Pax( 2 ) and Southwell. For fossil forms 

 see Felix, Foerste, Girty, Grosch, Hahn, Kasansky, Oppenheim, Parona & Crema 

 & Prever and Vinassa de Regnyf 1 ). 



For corals and coral-reefs see Drummond, Fryer, Giinther, Richarz, Spicer 

 and Wood-Jones. 



Pax( 1 ) describes Actinise from the West Indies - - Cerianthus 1, Condylactis 1, 

 Gyrostoma 1 n. (being the first record of G. from the Atlantic Ocean), Cysti- 

 actis 1 n. (the upper outgrowths on the column wall appear to be solid but 

 the lower ones are vesicles connected by a narrow endodermic canal with the 

 intra-mesenterial spaces), Bunodosoma 2 (1 n.), Asteractis 1, Aiptasia 4 (1 n.), 

 Lebrunia 1, Paradiscosoma 1, Eicordea 1, Phymanthus 1, Stoichactis 1 (sym- 

 biosis between Actinise and fishes occurs only in the tropics, and almost exclu- 

 sively between Stoichactidse and Pomacentridse), Zoanthus 3 (In.; in sociatus 

 outgrowths from the mesoglosa pass through the ectoderm to the subcuticula), 

 Isaurus 1, Parazoanthus 1, Epizoanthus 2. Palythoa is divided into 3 sec- 

 tions; Immersse, with coenenchyme so strongly developed that only the most 

 distal part of the polyp is free (7 sp., 1 n.) : Intermedia? in which the cosnen- 

 chyme forms, in the same colony, stolons and connecting lamellae, the polyps 

 are not completely retractile into the coenenchyme (1 sp.): Liberse (= Gemmaria 

 or Protopalythoa) with weakly developed coenenchyme, only in the form of 

 stolons connecting the bases of the polyps (1 sp.). The author regards as 

 belonging to Aiptasia only those Sagartiidse in which the sphincter is entirely 

 absent (contrary to Haddon); he divides the species of A. into two groups: - 

 Psilonemata, including those with smooth tentacles (e. g. leiodactyla n.), and 

 Dactyliophorse in which the tentacles bear annular or spiral thickenings (e. g. 

 annulata). In A. leiod. the primary and secondary mesenteries contained nume- 

 rous ripe testes and in the ccelenteron of the same specimen were 7 young; 

 this is the first instance of protogynous hermaphroditism recorded in Ac- 

 tinise. The author discusses the barriers to the distribution of Actinise, e. g. 

 reduced salinity and temperature, and remarks that he has examples of Priapus 

 equinus (= Act. eq.) and Paranemonia cinerea living in water the saline content 

 of which has been gradually reduced from the normal (35/ 00 ) to 4/ 00 . The 

 play of cold surface-water on a coast, and the topography and condition of the 

 sea bottom, are factors influencing distribution. Several of the genera of West 

 Indian anemones are of North Atlantic origin and have West Indian and Mediterra- 

 nean species, e. g., Cerianthus, GondyL, Priapus, Anem., Bunodeopsis, Aipt. The 

 Pacific elements in the W. Ind. fauna, especially Asteractis, Phymanthus, Actino- 

 thryx, Stoich., Ricordea and Isaurus, are regarded as relictse from tertiary 

 times, when the two regions were not separated by the Central American land 

 barrier. The deep sea Actinise of the Bay of Bengal exhibit strong resemblance 

 to those of the Atlantic, possibly a relic of the pre-miocene connection of these 

 seas. Bipolarity, in respect of littoral Actinise, does not occur and is im- 



