ABYLA. 49 



Abyla Leuckartii. pi. Ill, fig. 2. 



The superior nectociilyx is long and broad, but thin and compressed from side to side, 

 with six faces disposed around its longitudinal axis, and a single superior face which cuts the 

 anterior and posterior ones nearly at right angles. 



The anterior face (2 b) is flat and elongated, with four parallel sides. Its inferior angles 

 are produced into two curved, serrated points. 



The posterior face (2 a) is very narrow above, wider in the middle, and below ends in a 

 point at the margin of the hydrcecium. 



The antero-lateral faces are by far the largest; they are somewhat concave above, 

 convex in the middle, and concave again below. They are separated by well-marked serrated 

 ridges, concave forwards, from the narrow posterolateral faces. 



The superior face is hexagonal and somewhat concave ; its posterior side is very 

 small. 



The inferior surface exhibits an anterior quadrate division facing downwards, and 

 having in front the serrated points in which the lower angles of the anterior face end, 

 while behind are two larger serrated points developed from the inferior edges of the lateral 

 faces. Between these processes is the aperture of the nectosac itself, surrounded by four 

 short, incurved points. 



The posterior division is a triangular space which looks downwards and backwards and 

 is wholly occupied by the aperture of the hydrcecium. The latter extends through nearly 

 the whole length of the middle of the organ. Behind it is a large oval somatocyst with 

 vacuolated walls, which occupies nearly all the space between it and the posterior face, and is 

 connected by a duct from its apex with the coenosarc. 



The nectosac, cyhndrical, narrow, and rounded above, extends as far upwards as the 

 hydrcecium, and receives the short nectocalycine duct close behind its apex. 



Length of the proximal nectocalyx ■ . ■ iz i'lch. 



A single specimen of this species, consisting of a detached superior nectocalyx, was 

 taken in the South Pacific, not far from the east coast of Australia, in January, 1850. 



Only one large polypite was attached to the remains of the coenosarc, but several young 

 ones were in the course of development. 



I find no previous notice of this species, and I venture, therefore, to name it after the 

 able Professor of Zoology at Giessen, to whom and to his colleague Frey, we are indebted for 

 the most important improvement in the classification of the Animal Kingdom that has been 

 made since the time of Cuvier — the establishment of tiie Cmlenterata as a sub-kingdom. 



