44 



but they are not so large, being not over 3 mm. in length. Those in the coenenchyma of the 

 stem and branches are the largest, and their edges are nicely fitted, forming an even mosaic 

 surface which is finely granulated. 



Color. The colony is orange yellow, the axis light gray, and the spicules orange, 

 rarely white. 



Two specimens from Station 2S9 are referred with some doubt to this species. One is 

 bright red, and the other is almost white. The spicules agree with the above description. 



4. Acis serrata new species. (Plate VII, figs. 1, \a\ Plate XX, fig. 7). 

 Stat. 204. 4°2o'S., I22°58'E. near Island Buton. 75 — 94 meters. Sand. 



The colony (incomplete) is rudely flabellate in form, 10.3 cm. in height and 5.7 cm. in 

 diameter. The basal part is lacking. The main stem gives off a large simple branch 1.4 cm. 

 from the proximal end, which amastomoses with a branch higher up. 



A very small branch is given off a little above the first, but on the opposite side. 

 About 4 mm. above this another branch is produced, which gives off two branchlets ; and on 

 the opposite side of the main stem and 9 mm. above the last mentioned branch a large forked 

 branch is given off, one of the forks breaking up distally into a palmate structure. The main 

 stem breaks up into a similar flabellate structure about 5 cm. from its proximal end. The calyces 

 are mainly lateral in position, those on a given side being inclined alternately backward and 

 forward like the teeth of a saw, and are about 2.5 mm. apart from summit to summit. The 

 branches are slightly flattened, and appear to be more so than they really are, on account of 

 the lateral position of the teeth. The branches end in calyces. 



The indiviclual calyces are regularly conical in form, a tvpical one measuring 2 mm. in 

 height, and having a basal diameter of 2.2 mm. The calyx walls are filled with broad spindles, 

 most of which are vertical in position, although some extend from near the base to the 

 margin. The polyps are retractile, the tentacle bases being provided with slender spindles with 

 their proximal ends divaricated. Several of these sometimes tend toward the en chevron 

 arrangement. 



Spicules. These are spindles, rather than the irregular plates found in most other 

 species of the genus Acis. Those in the coenenchyma are heavy, with their edges nicely fitted 

 and ordinarily longitudinal in position ; but not uniformly so, especially near the bases of the 

 calyces. They rarely exceed 2.3 mm. in length. The calyx spindles are smaller than those of 

 the ccenenchyma, and sometimes appear to be regularly imbricated. But on other calyces on 

 the same branch they have their edges fitted as in a mosaic. 



Color. The colony is almost white, the axis grayish proximally and fading to almost 

 white on the distal parts. 



This species intergrades perceptably with the genus Muricclla. but seems to be more 

 like Acis than that genus, especially in the nicely fitted edges of the spindles. 



