118 INVEBTEBUATE MOBPHOLOGT. 



LITERATURE. 



A. POKIFBRA. 



Vosmaer. Porifera. Bronn's Klassen und Ordnungen des TMerreiclis. Leip- 

 zig u. Heidelberg, 1887. 



E. Haeckel. Die Kalkschwdmme. Berlin, 1872. 



F. E. Schnlze. Uhtersuchungen uber Bau und EntwicMung der Spongien. 



Zeitschr. filr wissenscli. Zoologie, xxv-xxxv. 1876-81. 

 A. Lendy. Obser'oations on the Structure and Classification of the Calcarea 



heterocmla. Quarterly Journal of Microsc. Science, xxxv. 1893. 

 E. von Lendenfeld. A Monograph of the Horny Sponges. London, 1889. 

 r. E. Sohulze. Beport onthe Hexactinellidce. Reports on the Scientific Results 



of the Voyage of H.M.S. Challenger. Zoology, xxi. 1887. 



B. Cnidaeia. 



GENERAL. 



L. Agassiz. Contributions to the Natural History of the United States. Vols. 



Ill and IV. Boston, 1860-62. 

 A. Agassiz. North American Acalephm. Illustr. Catalogue of the Museum of 



Comp. Zoology, ii. Cambridge, Mass., 1865. 

 E. Metsolinikoflf. Embryologische Studien an Medusen. Wien, 1886. 

 0. & K. Hertwig. Das Nervensystem und die Sinnesorgane der Medusen. 



Leipzig, 1878. 



HTDEOMBDUS^. 



G. J. AUman. A Monograph of the Qymnoblastic Hydroids. Ray Society. 



London, 1871-73. 



E. Haeckel. System der Medusen. I. Oraspedoten. Jena, 1879. 



H. N. Moseley. Beport on certain Hydroid, Aleyonarian, and Mad reporarian 

 Corals. Reports of the Scientific Results of the Voyage of H.M.S. Chal- 

 lenger. Zoology, II. 1881. 



W. K, Brooks. The Life-history of the Hydromedusoe. Memoirs Boston Soc. 

 Nat. Hist., III. 1886. 



A. Weismann. Die Entstehung der Sexualzellen bei den Hydromedusen. Jena, 

 1883. 



H. V. Wilson. The Structure of Cunoctantha octonaria in the Adult and Lor- 

 val Stages. Studies from the Biol. Laboratory Johns Hopkins University, 

 IV. 1886. 



E. Haeckel. Beport on the Siphonopliorm. Reports of the Scientific Results of 

 the Voyage of H.M.S. Challenger. Zoology, xxviii. 1889. 



A. Agassiz. The Porpitidrv and Velellidce of the Ouif Stream. Memoirs Mu- 

 seum of Comp. Zoology, viii. 1883. 



SOTPHOMBDtJS^. 



E. Haeckel. System der Medusen. II. Acrnspeda. Jena, 1880. 



