310 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 105 



oval suboral avicularium is mounted on a mound of varying prominence 

 and outlined by a line leading to the peristomial notch. A fewi 

 (about 6) small, widely spaced pores encircle the aviculiferous mound. 

 Ovicells globose, but damaged (or frontals missing), so data on them 

 is incomplete. 



This subspecies is named for its similarity to the species and its 

 smaller avicularia, from the Latin "brevis" (short). 



Measurements: Minimiun to maximum and average measure- 

 ments, in mOlimeters, are given below (for explanation see p. 271). 



Z-L, 0.922-1.340 (1.068) Se-Or-L, 0.216-0.259 (0.228, including 

 Z-W, 0.348-0.766 (0.593) notch) 



Av-L, 0.122-0.288 (0.212) PN-L, 0.036-0.072 (0.053) 



Av-W, 0.094-0.202 (0.140) PN-W, 0.043-0.072 (0.053) 



Pi--Or-L, 0.173-0.202 (0.188) Ly-L, 0.029-0.043 (0.035) 



Pr-Or-W, 0.209-0.230 (0.220) Ly-W, 0.072-0.101 (0.086) 



Se-Or-L, 0.158-0.216 (0.186, excluding Ov-L, 0.533-0.562 (0.518, only 3) 



notch) Ov-W, 0.475-0.518 (0.499, only 3) 



Se-Or-W, 0.202-0.274 (0.225) M-L, 0.079-0.202 (0.138) 



M-W, 0.079-0.173 (0.120) 



Zoarium: Encrusting and of ivory color. The holotype, which hasi 

 polypide remains within, is rather fragile and fragments easily. Itl 

 originally measured 9 by 9 mm. Another colony which is overgrown 

 by other calcareous Bryozoa is more sturdy. 



Zooecia: a salient rim outlines the zooecial boundaries. Although: 

 zooecia are large, they are smaller than those of S. ornatipectoralis. 

 The zooecia are 4-6-sided and longer than wide. Two kinds are 

 present — those with and those without ovicells, but they do noti 

 differ otherwise. A few zooecia overgrow others to form a second 

 layer. The zooecial frontal is a convex pleurocyst and pebbled in 

 texture. Ribs separate the closely set areolae. The avicularial 

 mound is raised above the zooecial frontal and is punctured by up 

 to three pairs of small pores around its base. 



Avicularium: A single suboral avicularium is present on eacb 

 zooecium with position and orientation identical in all cases. The 

 avicularium is cradled in the midline, just proximal to the peristomia]. 

 notch. It is flat against the chest, so to speak, or in a plane paraUel 

 with the frontal surface. The pleurocyst forms a loop around it and 

 continues distally on each side beyond to form a peristome, but thf 

 open end of the loop is wider in this variety than in the typical species 

 The avicularia are very broadly ov^al and of medium size. They are 

 smaller than those of the typical species. The back area is a lo\s 

 wide arc, and consequently the pivot bar is longer, relatively, than ir 

 the typical species. The mandibular part is broad and not verj 

 long. Moreover, the opening in the rostral floor is of a slightlj 

 different shape from that of the typical species. The chitin-rimmec 



