CLASS III. 

 SEA-NETTLES (A CA LEPHJE) \ 



BY Sea-nettles are understood radiate animals of a gelatinous, 

 transparent substance, which swim freely, and of which the organisa- 

 tion in parts that are frequently repeated usually indicates the number 

 four or its double. They "have no intestinal canal, but ordinarily a 

 blind stomach from which numerous tubes, mostly divided into 

 branches, run like rays to the circumference of the body (aquiferous 

 vessels, respiratory organs?). In some the sexes are separate: 

 others appear to be bi-sexual. Traces of a nervous system are 

 present at least in some; yet organs of sense, except appendages 

 which serve for feeling, are absent in many, whilst some have in 

 addition parts which by certain writers are considered to be organs 

 of hearing, by others organs of sight. 



Of the name Sea-nettles, Acalephce, Urticce marince, we have 

 treated above. With LAMARCK they form an order of the class of 

 radiate animals (Badiaires) , under which this writer also groups 



1 On this class may be compared especially : 



F. ESCHSCHOLTZ, System der Acalephen, Mit 16 Kupfertafeln. Berlin, 1829, 4to. 



C. G. EHRENBERG, Die Acalephen des rotken Meeres und der Organismus der 

 Medusen der Ostsee. Mit 8 colorirte Kupfertafeln. (Reprinted from the Physical. 

 Abhandl. der Konigl. ATcad. der Wissenchaften zu Berlin aus dem Jahre 1835). 



Histoire naturelle des Zoophytes. Acalephes par R. P. LESSON, av. pi. Paris, 

 1843, 8vo. 



J. G. WILL, Horce Tergestince, oder Beschreibung und Anatomie der im Herbste 1843 

 bei Triest beobachteten ATcalephen. Mit 2 Tafeln, Leipzig, 1844. 



EDW. FORBES, A Monograph of the British Naked- eyed Medusce, with figures of all 

 the species. London, printed for the Ray Society, 1848, fol. 



HUXLEY, On the affinities of the Medusce. Phil. Transact. London, 1849, *** IL 

 p. 413 &c. 



On the Siphonophorce : 



A. KOELLIKER, Die Schwimmpolypen, oder Siphonophoren von Messina. Mit 12 

 Tafeln, Leipzig, 1853, fol. 



R. LEUCKART, Die Siphonophoren, eine Zoologische Untersuchung, Giessen, 1853, 4to. 



R. LEUCKART, Zur ndhem Kenntniss der Siphonophoren von Nizza, Mit 3 Kupfertaf. 

 Berlin, 1854, 8vo. 



C. VOGT, Sur les Siphonophores de la Mer de Nice. Geneve, 1854. 



