6 AETEID.E. 



the spatulatc extremity is beautifully ringed. Mr. Busk 

 has noticed the pouch " like the bag of the pelican's beak," 

 which is formed by the membranous covering of the aper- 

 ture, and remarks that numbers of Navicula and Infusoria 

 are often found in it. The polypide, which is small and 

 delicate, has usually twelve tentacles of moderate length. 

 When the oral valve opens, a membranous sheath is first 

 pushed out, with a number of setiform processes round 

 its free extremity, which are thrown back and form a kind 

 of frill ; and then the polypide instantly darts forth : little 

 more than the pharynx and tentacular crown is protruded. 



The swellings on the creeping base in this species are of 

 moderate size, and generally occur at short intervals ; so 

 that the cells are set pretty closely together. 



Aetea anguina is developed in extraordinary profusion ; 

 and bunches of weed are often so thickly covered with 

 it as to appear powdered over with white. Masses of 

 Algae from Australia are invested in a similar way by the 

 kindred A. dilatata. 



AETEA RECTA, Hincks. 

 Plate I. figs. 6, 7. 



HirrOTHOA SICA, Couch, Corn. Faun. 102, pi. xix. fig. 9 : Johnston, B. Z. 



ed. 2, 292. 



AETEA RECTA, Hincks, Devon Cat., Ann. N. H. ser. 3, ix. 25, pi. vii. fig. 3. 

 STOMATOI-OKA GALLICA, L'Orbigny, Pal. Fran<j. Terr. Cr6t. v. 836, pi. 759, 



figs. 1-3. 



AETEA SICA, Norman, Quart. Journ. Micr. Sc. n. s. viii. 216. 

 AETEA ANGUINA p, FORMA RECTA, Smitt, (Efvers. K. Vet.-Akad. Forhandl. 



1867, No. 5, 281 & 297, pi. xvi. figs. 5, 6. 



Zooecia tall, nearly straight, very slightly dilated above, 

 truncate at the extremity ; surface coarsely ringed 

 below, the upper portion punctulate; area elongate, 

 occupying more than a third of the length of the cell ; 



