THE COLLECTION OF MISS H. GATTT. 137 



in a marsupial chamber enclosed bj four elliptical valre-like 

 segments. 



Locality. Cape of G-ood Hope ? 



This is a fine species, and attains a height of 3 inches*. The 

 pinnse towards the distal ends of the stems are generally the 

 longest, and are themselves usually pinnate, thus giving to the 

 hydroid a richness of ramification which is rendered still more 

 striking by the profusion of large, flower-bud-like gonangia 

 which are carried along the front of the pinnse. 



In the young female gonangia before the marsupial chamber 

 is closed in, the orifice of the gonangium may be seen on the 

 summit of a central conical process surrounded by the four 

 young lanceolate marsupial segments. 



Stnthecitim. 



Syntheoium eamosum, n. sp. (PL XII. figs. 3, 4.) 



TropTiosome. — Colony. Stem monosiphonic, much and irregu- 

 larly branched, pinnate throughout ; pinnse opposite, equidistant. 

 Hydrothecse deep, tubular, borne both by stem and pinnse. 



Gonosome. — Gronangia ovate, with the shorter to the longer 

 diameter at about 1 to 1|, strongly annulated, with the annular 

 ridges discontinuous where they meet a zigzag line on opposite 

 side of the gonangium, opening by a short tubular prolongation 

 of the summit. 



Locality. Tauranga, New Zealand. 



SyntJiecium ramosum attains a height of 6 inches. It is the 

 second well-determined species of the beautiful genus Byn- 

 thecium f. From Synthecium elegans it difiers by its greater 

 height and branching habit, and by the more globular form of its 

 gonangia, which in SyntJiecium elegans are considerably more 

 elongated, the transverse diameter being to the longitudinal in 

 that species as about 1 to 2. 



* A small specimen has been selected for the figure. 



t HeUer (Zoophyten und Eehinodermen des Adriatischen Meeres, 1868, 

 p. 35, pi. i. figs. 5, 6) describes, under the name of Bynamena tuhulosa, a 

 hydroid from the Adriatic which can scarcely be regarded otherwise than as a 

 species of Synthecium. He, however, represents a gonangium as springing 

 directly from the stem, and though he figures what appear to be the true 

 gonangia in their actual relation to the hydrothecse, he makes no reference to 

 these in his description, thus omitting the one essential character of the genus. 

 Altogether there is some obscurity in Heller's account, and when he tells us 

 that the species is not rare in the Adriatic, we can scarcely help thinking that 

 there has been some error in the location of his specimen. 



