HYDROIDA II 



6i 



Fig. XXVIII. Finds of Polyplumaria flabellata in the Northern Atlantic. 



one or two alternating apophyses. The apophyse proceeds asymmetrically from the base of a cauline 

 hydrotheca; this is surronnded by a pair of supracalycine sarcothecas, and a third sarcotheca situate 

 proximally and a little to the side of the median line, somewhat removed from the base of the hydro- 

 theca, on the side of the median line opposite to the apophyse. The hydrocladia are divided by trans- 

 verse nodes into internodia, which have about the middle a hydrotheca with a supracalycine pair of 

 sarcothecse, on low apophyses near the opening of the hydrotheca, and a proximal, unpaired sarcotheca 

 in the median line near the proximal end of the internodium. Tlie basal interuodium on the primary 

 hydrocladium has two proximal unpaired sarcotheca in the median line; 'at the base of this inter- 

 nodium's hydrotheca there appear, in fertile colonies, apophyses to the secondary hydrocladium, which 

 is of the same structure as the primary. The hydrothecce are on the hydrocladium about twice as 

 long as broad; on the stem somewhat shorter; the\- have a somewhat outward curving opening margin, 

 and are fused throughout their whole length with the internodium. 



The gonothecse are situate on the stem or close under the base of the proximal hydrothecse 

 on the primary and secondary hydrocladia; they have a short, often rudimentary stalk. The gonothecse 

 are pear-shaped, often curved, rounded off somewhat asymmetrically distally, with a broad opening; 

 they have two sarcothecae basally. 



Material : 



"Ingolf St. 24 63°o6' N., 56°oo' W., depth 1199 fathoms 2,4° 



55 63=33' N., i5°02' W., 

 98 65-^38' N., 26°27' W., 



316 

 138 



5,9 

 5,9° 



