470 MR. A. AV. WATERS OIST 



Stirparia dendrograpta, sp. n. (PI. LXVI. figs. 4-9.) 

 The stems grow from spreading stolons, and at frequent 

 intervals branches occur which may bear tufts of zooscia or may 

 produce other branches, and both the original stem and the 

 branches are divided into segments approximately equal, though 

 an internode below a tuft is frequently shorter than the others 

 From the base of most of the internodes there is a radicle or a 

 pair with frequently a cervicorn grapnel at the end. The colony 

 may grow to at least 50 mm. long, and the tufts 3-5 mm. long 

 originate from a zocecium entirely different from the later zooecia, 

 having more or less the character of a primary zooecium. When 

 first described the stem of Stirparia was considered to be the 

 equivalent of i-adicles, but this is not the case. 



The first zooecium (figs. 4, 6) has the area a little more than 

 half the length of the zooecium and is surrounded by eight very 

 long spines, often attaining about four times the length of a 

 zooecium. The spines of the first zooecium of a tuft are, however, 

 not bilateral, but are five on one side and three on the other, the 

 smaller number being on the side from which the next zooecium 

 grows. The next zooecium has a somewhat similar area, with 

 about five spines, and the avicularium is near the base of the area, 

 while the following zooecium approximates to the later zooecia in 

 having the avicularium somewhat higher than in zooecium no. 2, 

 thouglr still low down. In subsequent zooecia they are placed 

 still higher, their normal position in the older zooecia being at 

 the distal end on the outside corner. Typically they may be 

 terminal in the fourth pair of zooecia, or they may continue 

 lateral until the eighth, and after the appearance of a terminal 

 one subsequent zocecia are also generally at the corner of the 

 distal end. 



The avicularia are short with a distinct beak. 

 The branches of the tufts do not form a complete cup as in 

 S. exilis MacG. and S. zanzibariensis, sp. n., and the zocecia are on 

 the inside of the cup, whereas in the others they are on the 

 outside. The branches of the tuft dichotomise, and the spread- 

 out fan-shaped tuft is 3-5 mm. long, having often ten pairs in 

 succession. 



The zooecia are alternate and diagonal with the area a little 

 more than half the length of a zooecium, and the full number of 

 spines is three long ones at the distal edge, though many of the 

 lower zocecia may have one and the younger zooecia two spines ; 

 nor do the same number occur on both sides of a branch, the 

 zooecia on the outer zoarial side having more spines than those 

 on the inner ; with three on the outer, there is often only one on 

 the inner side. 



The ring-shaped oblique chitinous thickening, to which 

 Levinsen * refers as occurring in Bicellaria ciliata L., is often 



* Morph. & Syst. Studies on Cheil. Bry. p. 101. Levinsen puts B. caUculata 

 Lev. under Bugnla, but his PL iii. fig. 1 shows the character of Bicellaria in 

 having the long tubular proximal part. 



