■ > 1- " ENDEAVOUR " SCIKN I 111'' RKSULTS. 



Mesial sarcothecse adnate to the hydrothecee as Ear as the 

 margin ; free part short, slender, curved forward, terminal and 



lateral apertures distinct. Lateral sareotheea' adnate, saccate, 

 with two circular apertures, one directed forward, the other up- 

 ward ; both often more or less confluent with the wide lateral 

 aperture. Cauline sareotheea 1 similar to the laterals, two on the 

 racbis at the base of each hydrocladium, and a third at the back 

 of each axil. 



Gonosome — ? 



Colour. — Reddish-brown. 



This species closely resembles H. bailey i and IT. furcata, 

 between which it is to some extent intermediate. It may have 

 to be classed ultimately as a variety of H. furcata, when our 

 knowledge of the two forms is more extended ; at present it may 

 be provisionally regarded as a distinct species. 



A large colony of it was found accompanying Aglaoplienia 

 tasmanica, but whether it had commenced as a parasite on that 

 species, after the fashion of so many of its congeners, was 

 impossible to determine, the stems being matted together with 

 other growths. It divides in a purely dichotomous fashion, and 

 in most cases with considerable regularity, each division 

 bifurcating again at the same distance as its fellow from the 

 previous bifurcation. One specimen has divided four times, 

 all at regular distances, so that the final number of divisions is 

 sixteen. 



In the widely divergent branches and hydrocladia, the latter 

 being almost at right angles, it nearly resembles ]\ . furcata, 

 and both species differ from H. baileyi, in which the hydrocladia 

 are more ascending as well as more directed forwards. The 

 hydrothecre of the three species are much alike, but those of 

 H. furcata are broader in front view (in proportion to their 

 length), than in either of the others. The internodes are longer 

 in H. intermedia than in the others, and the hydrotheeffl on the 

 proximal parts of the hydrocladia, with their internodes, are 

 rather broader in front view than the more distal ones. 



In H. baileyi the base of each mesial sareotheea springs 

 directly from the back of the next hydrotheea, in the other 

 two species there is a distinct interval between ; in other words 

 the back of the hydrotheea does not quite exteud to the end of the 

 internode. In the " Catalogue of the Australian Hydroid 

 Zoophytes" it is stated in error, under M. baileyi, that 

 M. furcata is similar in this respect ; they are, however, figured 

 correetly. The central lateral teeth of the hydrotheea are some- 



