380 PROCEEDINGS OF THE ACADEMY OF [May, 



one conspicuous large nucleus, and likewise bears a tuft of short 

 cilia. 



The body cavity is voluminous in the trunk and the foot (but does 

 not continue into the peduncle of the latter). In it are free-floating, 

 non-cellular corpuscles, probably waste products. The cavity of the 

 arms is continuous with that of the trunk (figs. 9-11). Very few 

 connective tissue cells are present in the body cavity. 



FLOSCULARIA, Oken. 



Historical. 



Of the numerous writers upon this genus only the follo^\'ing have 

 considered to any extent the internal anatomy : Ehrenberg (1834. 1838) 

 Avi'ote with all the enthusiasm of the naturalist: "Sie sind einzeln, wie 

 seltene schone Blumen auf einer Wiese, und erfreuen gleich ihnen das 

 Auge des Beobachters." He found the mastax, oesophageal tube 

 and the stomach glands. Dobie (1849) gave a careful description with 

 good figures, and distinguished the infundibulum, yestibulum and 

 proventriculus ; he saw the cilia on the diaphragm. Leydig (1854) 

 added to this description in finding the contractile vacuole and the 

 longitudinal muscles. Gosse (1855) described in some detail the masti- 

 catory apparatus; and (1862) erroneously termed a vascular system 

 the narrow spaces of the body cavity in which float excretory cor- 

 puscles. The account of Moxon (1864) is much more thorough than any 

 of the preceding, and contains the discovery of the dorsal and lateral 

 antennae, correct position of the cilia within the infundibulum, and 

 occurrence of the nephridia with four flame cells on each side of the 

 body. Cubitt (1869) studied particularly the cilia within the coronal 

 cup. The papers of Grenacher (1869) and Cubitt (1872) added little 

 new. Eckstein (1884) gave a careful account of the hypodermis, 

 and the muscles and peduncle of the foot. Hudson and Gosse (1886) 

 add but little to the account of Moxon. The paper by Hood (1895) I 

 have not seen. The males have been described by Hudson and Gosse 

 and by Weber (1888). But the best of these descriptions, those of 

 Dobie and Moxon, leave much untouched in regard to the finer 

 anatomy. 



Anatomical. 



F. campanulata Dobie (PI. XX, figs. 27-35; PI. XXI) was the species 

 obtained in the greatest numbers, and on this account its anatomy 

 could be more fully determined than that of the others. F. conklini 

 Montg. (figs. 25, 26, PI. XX) was obtained at the same time, but it 

 is rather a difficult form to investigate on account of the large number 



