BY R. VON LEXDENFELD, PH.D. 593 



If we accepted the hypothesis of Weismann (1), many of the 

 Families described in the Suborder Hydropolypinse would have to 

 be placed here. 



I. SUB-FAMILY PENNARINJE. 



The Polypes possess a distal set of capitate and a proximal set 

 of filiform tentacles. The -filiform tentacles possess a longitudinal 

 stripe of high Ectodermal nettle-epithel on their dorsal side. 



42. GENUS PENNARIA. Goldfuss. 



Hydrophyton composed of a symmetrically ramified Hydro- 

 caulus, rooted by a creeping filiform Hydrorhiza, the whole invested 

 with a chitinous Perisarc. Hydranths flask-shaped, with the 

 filiform tentacles, constituting a proximal set, and arranged in a 

 single verticil round the base of the Hydranth, and the capitate 

 tentacles a distal set scattered on the body of the Hydranth. 



From the ordinary alimentary zooids, Medusas bud, which 

 become rudimentary in so far as the Manubrium is destitute of 

 oral appendages. The tentacles are four in number, rudimentary 

 and short. Ocelli absent. 



The structure of Pennaria cavolini was investigated hy Hamann 

 (2), and particularly by Weismann (3). 



The tentacles are bilateral symmetrical, with a ridge running 

 down one side. The Hydranths are not all alike inasmuch as the 

 terminal Hydranth produces the other Hydranths of the Pinna by 

 budding, but never a Medusostyl. The Medusostyles are exclusively 

 produced from the Proximal Zooids. 



1S9. PENNARIA AUSTRALIS. Bale. 

 Bale (1) describes this species from Port Jackson. 



(1) A. Weismann. Die Entstehung der Geschlechtszellen bei den Hydro- 

 medusen. 



(2) Hamann. Der Organismus der Hydroidpolypen Jenaische Zeit- 

 schrift. Band XV., Seite 520. 



(3) A. Weismann. Die Entstehung der Geschlechtszellen bei den Hydro- 

 medusen. Seite 119-126. 



