THE COLLECTION OE MISS H. GATTT. 139 



impressed with narrow, closely set, transverse constrictions which 

 project into the cavity of the tube. The gonangia are abundantly 

 developed in the specimen, and, as Miss Gatty has remarked to 

 me, it is deserving of note that the Sargassum on which it grows 

 is a rooted species, while on the floating Sargassum of the Grulf 

 Stream Sertularice are rarely if ever found with the gonosome 

 developed — a fact not without significance in connection with 

 the invariable absence of fruit in the floating seaweed, and its 

 presence in the rooted one. 



>S^. minima comes very near to S. megalocarpa, from which it is 

 chiefly distinguished by its wider and more extensively adnate 

 hydrothecge. 



SeETTJLAEIA TJlSriLATEEALIS, n. sp. (PL XIII. figs. 5-7.) 



TropJiosome. — Stem monosiphonic, slender, sending off from 

 one side very numerous slender ramuli, which are dichotomously 

 branched. Hydrothecse nearly cylindrical, divergent, with the 

 epicauline side adnate for about half its height to the internode ; 

 apocauline side of orifice deeply emarginate. 



Gonosome. — Gronangia borne by the internodes just below the 

 hydrothecse, in the form of an inverted compressed cone whose 

 axis terminates distally in a tubular orifice, on each side of which 

 the edges of the gonangium are prolonged in the shape of a 

 strong horn-like spine. 



Localities. New Zealand and Australia. 



S. tmilateralis occurs in large close tufts which attain a height 

 of upwards of 6 inches. Each tuft is formed by a multitude of 

 slender filaments carrying closely-set pairs of hydrothecse along 

 their entire length, and sending off at short intervals equally 

 slender ramuli which are dichotomously branched. These ramuli 

 are entirely confined to one side of the main filament, whose 

 characters they exactly repeat in their slenderness, and in the 

 form and distribution of the hydrothecse. 



The lateral compression of the gonangia causes these to assume 

 a triangular form, the base of the triangle being situated distally, 

 and having its two angles continued into a strong curved horn. 



Sebtulaeia ceinis, n. sp. (PI. XIV. figs. 1, 2.) 

 Trophosome. — Main stem very slender, monosiphonic, sinuous, 

 subdichotomously branched, carrying along its length short 

 alternately disposed ramuli, which soon subdivide into somewhat 

 flabeUiform groups of hydrotheca-b earing ramuli. Hydrothecse 

 deep, adnate to the internode for about two thirds of their epi- 



