44 



Dendronephthya parvula, Henderson. 



The specimen, which is undoubtedly young, has a short stalk and a very 

 loose, irregular polyparium. The total length of the colony is 19 cm. and 

 the maximum breadth is 2 cm. 



The rigid stalk is short, measuring only 5 mm. in length. It has a 

 sloping base of attachment as if it had been growing round some branch or rod- 

 like structure. At the edge of its base one or two small stolons and the re- 

 mains of a few others can be seen. Its upper portion is hidden, collar- wise, by 

 the reflexed lower branches. 



The polyparium is very loose and of no fixed shape, consisting of a slender 

 stem and a few main branches which are all developed in one plane. From 

 the slender stem two large branches are given off almost at the same level on 

 opposite sides ; the stem rises intact for a short distance, and then apparently 

 divides into two portions, one of which is much larger than the other and has 

 lost its tip. It may be that there are not two branches, but that the stem 

 has been bent slightly to one side when the top branch was given off. Small 

 branches arise from the main branches and from the surface of the stem. The 

 two lowest main branches are flattened leaf-like structures and are reflexed, 

 forming a collar to the upper part of the stalk. Their broad bases of attach- 

 ment almost surround the stem, leaving only a small portion free. 



Polyps may occur in groups of two to eight, most frequently of two, or 

 they may occur singly on the ends of small branches, and they also occur singly 

 on the free edges of the flattened, leaf-like branches. The polyps are roundish 

 bodies, slightly longer than broad, measuring on an average 0-80 mm. in height 

 and 064 mm. in breadth, and are placed on stalks, which measure up to 1 7 mm. 

 in length, at an angle which is almost right but in a few cases becomes acute, 

 owing to the polyp-head being slightly more bent towards the ventral surface. 

 The spicules are arranged in the following manner : Round the base of the 

 polyp they meet at a very obtuse angle, forming eight incomplete double rows 

 in each of which there are one or two pairs of converging spicules ; then there 

 is a ring consisting of rows of horizontally placed spicules ; above this rise 

 eight groups of .spicules, each group consisting of a curved spicule lying horizon- 

 tally which forms a base for the triangle formed by the spreading ends of two 

 upper converging spicules ; a third spicule lies in the triangle thus formed, 

 while another lies in the space between adjacent triangles. The upper pair of 

 spicules, of which one is slightly longer, project for a considerable distance be- 

 yond the polyp. The projecting spicules are flattened spindles, either straight 

 or curved, with numerous small spines ; they measure up to OS mm. in length, 

 while the other polyp-spicules average 0-32 nun. in length. On the aboral sur- 



