67 



The stalk is short and thick, measuring 13 nnn. in length, and has a broad 

 base of attaelnneut. It is graniilar in texture, but there is a series of larger 

 sj)ic'ules more or less regularly arranged on the surface, giving it a peculiar 

 stringy appearance. Its upper portion is 

 hidden by reflexed lower branches. 



The polyparium is regular in outline, 

 roughly four-sided in shape, and greatly 

 flattened in one ])lane. The lower branches 

 are Hatteued, leaf-like or ridge-like struc- 

 tures. Two of them are very large, prac- 

 tically surrounding the stem, their free 

 ends overlapping where they meet. They 

 are reflexed and form a collar to the 

 upper part of the stalk ; they have broad 

 bases of insertion which leave two very 

 small spaces between them ; directly 

 above this space at each side there arises 

 a small branch, flattened in its upper, but 

 more rounded in its lower portion. Al- 

 most immediately above this the stem 

 gives off two large branches, and after 

 rising for a short distance entire, divides 



into two large branches. These four large primary branches repeat the structure 

 and branching arrangement of the stem, though in a less marked degree. At 

 the base of one of the two lower primary branches there is an arrangement of 

 flattened, leaf-like branches similar to those on the stem, though rather less 

 developed. From the upper surface of each of the largest lower .flattened 

 branches a small branch is given off which repeats the structure of a large 

 primary branch. All over the surface of the stem and primary branches 

 small secondary branches arise at an angle which is practically right, and by 

 their division give rise to the twigs on which the polyps are placed. 



The polyps are arranged in small groups of three to five, on widely diverg- 

 ing stalks, the appearance of the colon}- thus becoming very open. On the 

 leaf-like branches the polyps occur singly on the edge or in small groups on the 

 upper surface. It is difficult to determine the exact number of some groups as 

 there is often a polyp standing directly in the angle formed by two polyp-bear- 

 ing twigs. The heads, low, oval, 056 mm. high, 064 mm. broad, are placed at 

 an obtuse angle on a stalk which may be 2o mm. long, but which varies con- 

 sideral)ly in length. The spicules are arranged in the following manner : There 

 are eight double rows of spicules ; in each double row at the base of the polyp 

 there are two pairs of converging spicules ; then comes a ring of two rows of 



Fig. 35. D. longispiua. 



