CLADOCARPUS. 49 



had been developed in the specimens obtained, which were possibly ex- 

 amples of young individuals ; but though the entire colony might increase 

 in size with age, it is not probable that older specimens would present 

 any important change of form. 



In the absence of a gonosome the reference of the species to Aglaophenia 

 is provisional.* 



CLADOCARPUS Allman nov. gen. 



Generic Character. Trophasome. — Hydrosoma pinnate, plumose. Ne- 

 matophores fixed ; supracalycine neraatophores one on each side of the 

 orifice of the hydrotheca ; mesial nematophores either adnate to the front 

 of the hydrotheca or free. 



Gonosome. — Gonangia not included in corbulai, but borne on the sides 

 or at the base of special protective branches (phylactogonia), which are 

 appendages of the pinnae. 



The genus Cladocarpus was originally defined by me for the reception 

 of a remarkable Plumularidan obtained in tbe eastern parts of the North 

 Atlantic during one of the expeditions of the " Porcupine." t Its most 

 important character is found in the possession of peculiar branching ap- 

 pendages, which are destined to support the gonangia, or in some other 

 way to afford protection to them. It is convenient to have a special name 

 for these appendages, and that of " phylactogonium " is suggested by the 

 function which devolves upon them. 



The phylactogonia differ essentially from the corbulse, whether open or 

 closed, of the Aglaophenite ; for they are not, like corbulie, metamorphosed 

 pinnge, but appendages superadded to the normal pinnae. 



In Kirchenpauer's subgenus Macroryuchia the gonangia are also borne 

 on special appendages, but the pinnae which in Cladocarpus retain their 

 normal form, and support the phylactogonia, are here suppressed, and are 

 represented only by short stunted processes destitute of hydrothecaj. 



The macrorychial Aglaopheniae of Kirchenpauer are further distinguished 

 from Cladocarpus by the fomn of the mesial nematophores, which are very 

 long, usually fiir surpassing the height of the hydrotheca3, and which, as 

 Kirchenpauer first pointed out, are always provided with a lateral as well 

 as a terminal orifice after they cease to be adnate to the hydrotheca. 



* See Note on p. 56. 



t Report o;i the Hydroida collected during the Expeditions of H. M. S Porcupine, Trans. Zool. 

 Soc. Lond., Vul. VIII. Part VIII. 

 7 



