18 i\Ir. A. W. Waters on Bnjozoa from 



surface there are fairly larjije avieularia witli semicircular or 

 spatulatc mandibles. The mound over the middle of tlic 

 zooccium contains the avieularian chambers. There are oral 

 as Avell as avieularian ghands and 13 tentacles. The ovieell 

 is depressed, usually umbonate. The appearance is very 

 similar to that of Lcj/nilia iiian/orit/fcrn, Q. & G., hut in that 

 species the umbo is an avieularian chamber openiu}::^ forwards, 

 Avhcreas in L. cVivosn there is an avicularium within the 

 aperture. The ovieell is mueli raised in L. maryarit'ifera 

 and has not a marked umbo like that of clivosa. Sections 

 of the o;rowing end show several interesting points. At the 

 distal end of the young zooecia there is a dark cellular 

 structure bounded by a row of transparent cells, showing in 

 some cases a nucleus at the base. From this arise outgrowtlis 

 also surrounded by similar transparent cells (fig. 5), and 

 in several cases one or two such outgrowths are seen near 

 the corner of the distal wall, but in one ease (fig. 6) there 

 are three outgrowths. At the position of these outgrowths 

 the rosette-plates will be formed, but as yet it is too early to 

 speak of ro>ctte-plates. These outgrowths as they increase 

 coalesce, and thus the basal wall of the next zocEcium is 

 formed. At the lateral walls similar but more numerous 

 outgrowths are formed, Mhich also coalesce. As I have in 

 previous papers indicated, we must compare this with the 

 groAvth in Beania and other species connected by tubes ; and 

 as exi)laining this I again refer to an exact drawing of a 

 specimen of Beunin magellanica, Busk {'' On the Bryozoa of 

 the Bay of Naples," Ann. & ]\Iag. Nat. Hist. ser. 5, vol. iii. 

 pi. xii. fig. 1, 1879). I'liere is, however, an important 

 difference> for in L. c/iyo^fl the calcareous^ basal wall and 

 the lateral walls are formed before this new^ growth from the 

 zocceial chaiid)er commences ; and this may be taken as 

 typical of the zooecial growth of a large section of the 

 Bryozoa. 



Even in zooecia in which there is still this growing tissue 

 there are ovaria touching this tissue and thus showing at 

 what a very early stage the ovaria commence to grow. In 

 Smittia prastans, Hincks, ovaria also are found near the 

 growing end of the young Z)oecia. 



The oral glands show little or no lumen (fig. 4) in the 

 sections cut. In various species orjl glaiuls have only been 

 seen with small cells on the inner wall, in others they 

 contain a considerable mass of homogeneous matter, so that 



* Compare Nitsche, " Beitrage zur Keuntniss der Bryozoen," Zeitscli. 

 fiir wissenscli. Zool. vol. x.\i. pi. i. fig. .5. 



