ON THE HYDROIDS OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 17 



near the base, but profusely branched distally. Except in the following unimportant 

 details, the specimens agree with those previously described. While the annulations 

 at the bases of the branches are well marked, the constrictions in the internodes are 

 neither so frequent nor so distinct as those of former specimens. The gonangia closely 

 resemble those described and figured by Nutting (1904, p. 85). The annulations vary in 

 number, in some cases disappearing altogether in the proximal portion of the gonangium. 

 The teeth at the summit of the gonangium also vary in number ; sometimes they seem 

 to be absent, as in Kirchenpauer's specimen (1884), sometimes two are present, as 

 described by Nutting, but in the present specimens three is also an occasional number. 



Localities. — {a) Falkland Islands, Port Stanley. Date, 8th January 1903. {h) 

 Cape Pembroke ; shore. January 1903 to January 1904. 



It is interesting to note that the present specimens were found in the same locality 

 as were those from which the original description of the species was made by Kirchen- 

 PAUER some twenty years ago. 



Sertularellajiliforinis, var. reticulata, n. var. 



Several colonies referable to this species have been found, usually growing on 

 polyzoon crusts, in two localities. Of the colonies, which ai-e profusely branched and 

 loaded with gonangia, those from locality (a) reach a height of from 5 to 6 cm. 

 while those from {h) are considerably smaller. The hydrothecse are adnate to the stem 

 for 0'27 mm. and free for 0'15 mm., while at the opening their diameter is 0*1,5 mm. 

 They have three teeth, thus differing from Allman's (1888) description, where two broad 

 cusps are mentioned, and agreeing with Nutting's 1904) description of a portion of 

 Allman's specimen. The present specimens vary slightly from those described by 

 Nutting in habit and in gonangia. The majority of those from (a) and all the specimens 

 from {h) have closely interwoven and anastomosed branches, and thus present a matted, 

 net-like appearance. 



Gonosome. — The gonangia arise from each side of and just below the hydrothecse. 

 They are top-shaped, 1*7 mm. long, with eight or nine large annular ridges, the widest 

 portion occurring about the second or third ridge from the distal end, where the 

 diameter, not including the ridge, is 0"7 mm. They are surmounted by a tube 0'45 

 bo 0'5 mm. long, whose diameter gradually increases from base to margin, where it is 

 0'25 mm. wide. 



Localities, etc.— {a) Burdwood Bank. Lat., 54° 25' S. ; long., 57° 32' W. ; 56 

 fathoms. Date, 1st December 1903. (b) Eight miles north of Dassen Island, Cape 

 Colony; 35 fathoms. 18th May 1904. 



SertulareUa gayi, Lamouroux, 1821. 



A strongly fascicled specimen 13 cm. high by 7 cm. broad is referable to this 

 species. The general habit of the colony, with rigid stem 2 nini. in diameter 



(roy. soc. edin. trans., vol. xlv., 535.) 



