with Observations on Australian Hydroids. 87 



cata, A. 'plumosa, A. ramosa, and A. formosa ; those wliicli 

 have a closed corbula are A. parvula, A. pluma, A. Mac- 

 Gillivrayij A. criicialis, and A. Lendenfeldi (A. Kirchen- 

 pauri, Lend.) 



Lytocarpus, Allman, modified. 



Trophosome as in Agiaophenia, 



Gonangia protected by nemotocladia, which consist of 

 modified hydrocladia, and do not produce secondary ribs. 



There are two Australian species described in the *' Cata- 

 logue" which will have to be placed under this genus — 

 namely, A. urens and A. phcenicea. In the former the 

 scattered gonangial pinn^ bear several hydrothecse below 

 the gonangium, but above it are abbreviated and provided 

 with nematophores only. A. "phoenicea has every third 

 pinna on each side of the fertile branches altered into a 

 nematocladium, bearing only a single hydrotheca below the 

 gonangium, and having the rest of its length recurved, and 

 armed with two series of large nematophores. In L. racemi- 

 ferus (Allman) the nematocladia are all brought together into 

 a particular part of the branch, forming a pseudo-corbula. 

 In this species each joint of the nematocladium bears three 

 sarcothecse, the mesials of the suppressed hydrothecse being^ 

 retained as well as the laterals. 



There is a striking resemblance between the nematocladia 

 of L. phoeniceiis and those of A. divaricata. In the 

 " Catalogue" I have cited these species, along with A. urens,. 

 A. patula (K.) and Pleurocarpa, as showing the stages in the 

 transition between species with naked gonangia and those 

 with a true corbula ; but this seems to be an error, caused 

 by superficial resemblances, since the nematocladia of 

 L. phoeniceus and its allies are altered pinnge, while those of 

 A. dAvaricata are modified mesial nematophores, and those 

 of Pleurocarpa are, according to Allman, homologically 

 distinct from either. 



Cladocarpus, Allman. 



Trophosome as in Agiaophenia. 



Gonangia protected by phylactogonia (special protective 

 branches which spring from the hydrocladia). 



In all the known species of this genus the phylactogonia 

 spring from the proximal internode of an ordinary hydro- 

 cladium, and are curved over the gonangium, which may be 



