ON THE HYDROIDS OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 25 



and free for a short distance distally. The nemcUojyJiores, of the usual trumpet-shaped 

 type, have an internal septum which gives them a two-jointed appearance and are 

 arranged as follows : — Three on each thecate internode, two lateral and distal, and reaching 

 a considerable distance above the level of the hydrotheca margin, the other median and 

 proximal and arising just above a slight bulge in the internode ; one on each athecate 

 internode, except where two such internodes are developed in succession, when the 

 proximal one is unprotected ; on the branches there are two lateral nematophores on 

 the hydroclade-bearing process and one in the angle between this and the branch, but 

 in the next highest internode. 



Gonosome. — Not observed. 



Locality, etc. — Entrance to Saldanha Bay, Cape Colony, in 25 fathoms. 21st May 1904. 



The present specimens approach in general structure A. decussata, Kirch. (1876, p. 55), 

 A. joknstoni, Kirch. (1S76, p. 55), and A. irregulares, Quelch (1885, p. 8), for in the first 

 and last of these the hydroclades, although generally two in number per internode, may 

 vary from two to three or even four. In our specimens the hexastichous arranwemeut 

 appears to be constant, and the species is distinguished from those mentioned above in 

 having exceedingly strongly developed internodal septa. 



We have named the above form after Professor Cl. Hartlatjb of Heligoland, author 

 of the report on the Belgian Antarctic Expedition hydroids, to whom we are indebted for 

 occasional assistance. 



Antennopsis scotia), n. sp. (PI. III. figs. 3, 3a.) 



Two much weather-beaten colonies of a pale brownish colour, growing on a sponge 

 fragment and reaching a height of 9 cm. and 4 cm. respectively. Both the colonies are 

 badly weathered ; the smaller is overgrown for half its length by the sponge, while the 

 remaining portion is destitute of hydroclades. Here and there at irregular intervals a 

 branch springs from the main stem, but without any definite arrangement. Of the larger 

 specimen about 5 cm. are free from the encircling sponge, and on this almost bare surface 

 a few hydroclades occur. The stem and branches are strongly fascicled, about 2 mm. in 

 diameter, but the coenosarc shows no .signs of caniculation (Nutting, 1900, pp. 68 and 

 72). The hydroclades arise irregularly from all sides of the stem, springing from 

 the outer tubes of the fascicle. Proximally they have from three to six athecate 

 internodes separated by straight nodes, the distal of these, and sometimes that 

 beneath it, being greatly elongated and bearing a number of nematophores varying from 

 two per joint to five on a single long internode. Above this athecate portion the 

 hydroclade is divided by alternate slanting and straight nodes into fairly regular 

 internodes, every alternate one of which bears a hydrotheca. The hydrothecse are 

 stoutly campanulate and large, 0'22 mm. in length by 0"22 to 0-25 mm. in greatest 

 diameter, with entire rim and oblique opening, adnate up to the distal end of theii- own 

 internode, and afterwards free — the free portion lying over against the intermediate 

 internode, the rim reaching the level of the proximal end of the next hydrotheca- 



(ROY. SOC. EDIN. TRAXS., VOL. -KLV., 543.) 



