AETEA. 3 



FALCARIA /3, Oken, Lehrb. Naturg. Zool., Abth. ii. 91, 1815. 

 CMRCARIPORA (for Aetca tntncata &e.), Fischer, Arch. Mus. Hist. Nat. ii. 

 292-313. 



GENERIC CHARACTER. ZOCECIA calcareous, tubular, 

 erect, with a membranous area on one side; distributed 

 along a more or less adherent, creeping fibre, dilated at 

 intervals ; orifice terminal. OCECIA none. 



THE polypide in this genus is of the simplest type. 

 There is no gizzard; the long oesophagus leads at once 

 into the digestive sac, which is but slightly dilated, and 

 tapers off below; the number of tentacles is small. During 

 retraction the polypide is not folded upon itself, but 

 stretches straight downwards within its cell. 



The structure recalls in many respects that of the 

 simpler Ctenostomata, such as Valkeria. 



Seven species of Aetea have been described, of which 

 three occur on our coasts. The genus has representatives 

 in South America (Patagonia), West Indies*, Australia, 

 and Africa, as well as in Europe, where it reaches far north. 

 A. anguina ranges from Norway to Zanzibar, and is 

 equally at home in Australia and in our own seas. 



The specific distinctions are founded on differences in the 

 size and shape of the cell, and especially in the shape of 

 the oral extremity, in the comparative length of the mem- 

 branous area, and in the characters of the surface. 



We may perhaps regard the straight forms (in which the 



gained by the restoration of her lost honours to Actea to compensate for the 

 confusion that would be caused by the displacement of a well-established 

 term. I therefore retain the name aa it stands in Lamouroux's works, and 

 as it is known to science. 



* D'Orbigny records the occurrence of a species in Cuba, which he names 

 A. Americana; but his description is so meagre that it is impossible to 

 decide whether it is really distinct. It is said to be nearly allied to 

 A. anguina, but to hare the cells rery much smaller, and narrower at the 

 extremity. 



B 2 



