ABYLA. 47 



the right-hand side, a small serrated ridge projects perpendicularly and ends below in the 

 pointed lower extremity. 



The hydroecium is bell-shaped, and its axis is directed obliquely upwards and forwards. 

 Its summit does not quite reach the middle of the organ. A narrow tubular somatocyst, 

 without processes, continues its direction towards the solid angle formed by the junction 

 of the two supero-lateral faces. 



The nectosac oblong, narrow, rounded above, is inclined parallel with the somatocyst, 

 and extends about as far ; its lower opening is circular. The distal nectocalyx was not obtained. 



The hydrophyllium in the most perfect specimens had the form of a quadrilateral pyramid, 

 with its apex truncated, to form a flat, quadrangular area, whose angles are prolonged (PI. II, 

 fig. 3 b). 



The peduncle of the polypite traverses the centre of the upper face of the hydrophyllium, 

 and dilates within it into rather a wide phyllocyst, before becoming continuous with the 

 polypite. The anterior face of the pyramid is excavated by a deep arched notch, extending 

 nearly to its upper boundary. The edge of the notch is serrated. The produced angles 

 of the upper face are separated on this side by a much deeper depression than on any 

 of the other three. 



Length of the proximal nectocalyx . . /j inch. 



Length of the hydrophyllium . . 55 „ 



The end of the ccenosarc of the single specimen of this species (taken off the south-east 

 coast of New Guinea) which I observed, was torn off. The largest or terminal zooid is figured 

 in 3 5 ; it possessed a gonophore (3 c) of ^i\\ of an inch in length. 



In my notes I find it stated as above, that the hydrophyllium is developed round the 

 pedicle of the polypite. This is so unusual a circumstance, however, that I suspect I have 

 confounded the pedicle of the polypite with the cccnosarc. 



Abyla trigona. pi. Ill, fig. 1. 



Abyla trigona, Quoy and Gaimard, 18.27. 

 — — Esch.scholz, 1829. 



Diphyes abyla, Quoy and Gaimard, 1833. 

 Amphiroa alata (?), Lesueur, 1830. 



The proximal nectocalyx has six faces arranged around the inferior moiety of its longi- 

 tudinal axis. Of these the anterior (fig. 1 «) is an oblong parallelogram with its inferior 

 angles produced and a little divergent; the posterior (fig. I *) is triangular, with its 

 apex downwards ; the antero-lateral faces are pentagonal ; the postero-lateral, rhomboidal. 



The superior extremity of the proximal nectocalyx is cut into four facets — an anterior, 

 hexagonal with concave lateral edges; a posterior, quadrilateral, meeting the last in a transverse 

 ridge ; and two lateral rhombic faces, which fit in between the anterior and posterior facets 

 of the superior surface above, and between the antero-lateral and postero-lateral facets below. 



The inferior face presents an anterior quadrilateral facet, in the midst of which is the 



