known Species 0/ Spongilla. 79 



gilla^'' instituted for the genus by Lamarck in 1816 (No. 5), 

 has taken precedence of all the rest, whereby we now have 

 Spongilla jliiviatilis and 8. lacustris. 



It was not, however, until the improvements of the micro- 

 scope ushered in an era of minuter observation that Spongilla 

 was more particuLarly examined, when Dr. Grant (my kind 

 friend and able teacher) published his "Observations" in 

 1826 (No. 6). After this, Meyen, in 1839, pointed out that 

 the crust of the sphajrula or seed-like body (statoblast) was 

 composed of vertically placed spicula l-250th to l-200th of 

 a millim. broad, at whose extremities, near the circumference, 

 more or less toothed little disks are formed (PI. VI. fig. 

 11, a, &), and further that, " besides the larger siliceous spicula 

 within the substance of the sponge, there exist more delicate 

 ones of l-16th to 1-lOth of a millim. long, having upon 

 their surface little points which elongate as their age in- 

 creases " (apud Johnston, No. jlO, p. 154, footnote). Here 



21. — 1866. BowEBBANK, J. Monograph of tlie British Spongiadae, 



Yol.ii. pp. 339-344, Spongilla Jiuviatilis and S. lacustris; ib. vol. i. 



p. 262, spicula of the ovaries of Sjiotu/illa ; pi. ix. figs. 201- 



227, pis. xxii. and xxiii. figs. 217-322 (figures of the " ovaries"). 

 22. — 1867. Gray, J. E. "Notes on the Arrangement of Sponges," 



Proc. Zool. Soc. Loudon, May 9, p. 550, &c. (Potamospungia, 



classification of). 

 23. — 1867. James-Olark, H. J. ^^ Spongice ciliatce &?, Infusoria flageU 



lata^'' Joiu-n. Boston Soc. Nat. Hist. vol. i. pt. 3, pis. ix. and x. 

 24. — 1868. Carter, H. J. " On a Variety of Spongilla Meyeni from 



the River Exe, Devonshire," Ann. & Mag. Nat. Hist. ser. 4, 



vol. i. p. 247. 

 25. — 1870. BowERBANK, J. Monograph of the British Spongiad^, 



vol. iii. pis. lix. and Ix. 

 26.— 1874. Carter, H. J. " On the Nature of the Seed-like Body of 



Spongilla, &c," Ann. & Mag. Nat. Hist. ser. 4, vol. xiv. p. 97. 

 27. — 1875. Carter, H. J. " Notes Introductory to the Study and 



Classification of the Spongida," ibid. vol. xvi. p. 1, &c. : Potamo- 



spongida (pp. 187, 190, and 199). 

 28. — 1877. Dybc.vski, W. " Ueber Spongillen der Ostsee-Provinzen," 



Sitzungsber d. Naturf. Gesellsch. zu Dorpat, Bd. iv. Heft 2, 



1876, p. 258, Heft 3, 1877, p. 527. 

 29. — 1878. ScHULZE, F. E. " Untersuchungen fiber den Bau und die 



Entwicklung der Spongien. Die Gattung Halisarca," Zeitschrift 



f. wiss. Zoologie, Bd. xxviii. 

 30. — 1879. Metschnikoff, E. " Spongiologische Studien," ibid. Bd.xxxii. 



p. 349, Taf. xx.-xxiii. 

 81. — 1879. Carter, H. J. " On the Nutritive and Reproductive Pro- 

 cesses of Sponges," Ann. & Mag. Nat. Hist. ser. 5, vol. iv. p. 374. 

 32. — 1880. Dybowski, W. " Studien fiber die Spongien des Russischen 



Reiches mit besonderer Berucksichtigung der Spongien-Fauna des 



Baikal-Sees," Mem. Acad. Imp. d. Sc. de St. Pi5tersbourg, 7* 



S(5rie, t. xxvii. no. 6. 



7* 



