336 Mr. J. Miers on the genus Lyciuni. 



diameter, and the tail about three times this diameter in 

 length. 



Dujardin saw and has figured these cells and their filaments 

 en masse, and observed polymorphism in the former, from which 

 he compared them to a Volvox, and inferred that the use of the 

 filaments was " pour determiner a la surface le deplacement de 

 l'eau et par suite les courans dans les oscules " (Ann des Sc. Nat. 

 2nd ser. t. x. pp. 9, 10). But he did not see these filaments on 

 the surface of Spongilla, nor on the lining membrane of its 

 canals, neither have I been able to detect them in either of these 

 situations. Huxley has also described and figured similar bodies 

 in a species of " Tethya" (Ann. and Mag. of Nat. Hist. vol. vii. 

 p. 373, 1851), which he considers " spermatozoa/' and I know 

 not what else to consider those above described, if they are not 

 the spermatozoa or zoosperrns of Spongilla. 



The portions of Spongilla which were thrown into the tank I 

 had had by me for seven or eight years, and the period during which 

 the ova while in their capsules will retain their vitality, if not 

 some parts of the dried skeleton also, seems almost indefinite. 



Bombay, 28th July 1854. 



EXPLANATION OF PLATE XI*. 



Fig. 1. Zoosperm of Spongilla about 1 -4300th inch iu diameter, magnified ; 



passive condition. 

 Fig. 2. Ditto ditto active ; stationary or progressive. 

 Figs. 3, 4. Ditto ditto polymorphic. 

 Fig. 5. Ditto ditto ditto, showing the insertion of the tail drawn forwards 



by the polymorphism of the cell. 

 Fig. 6. Portion of Spongilla, magnified, presenting tails of zoosperrns in 



active motion. Natural size about 1000th of an inch in diameter. 



XXXI. — On the Genus Lycium. By John Miers, Esq., 

 F.R.S., F.L.S. &c. 



[Concluded from p. 194.] 



3. Macrocope. Corolla tubus ladniis limbi brevior : stamina longe 

 exserta. Species omnes Neogece. 



* Filament a imo glandula linear i carnosa margine ciliata donata. 



60. Lycium filifolium, Gill. ; — inerme, glaberrimnm, ramosis- 

 simum, ramulis virgatis, cinereis, striatis, nodis cupulatis ; 

 foliis alternis, vel subfasciculatis, longe et anguste linearibus, 

 utrinque acutis, crassiusculis ; floribus solitariis, gracile pe- 

 dunculatis, calyce poculiformi, subpubescente, membranaceo, 

 5_6-costato, 5-6-dentato, dentibus obtusiusculis, ciliatis ; 



