Bryozoa. 443 



Membranipora (Callopora) Whiteavesi Norman. 



Callopora Whiteavesii Norman, Nat. Hist. of East Finmark, Polyzoa 

 (Annals Nat. Hist. 7. S., Vol. XI, 1903), p. 589— 

 90, PI. Xin, fig. 9. 



Membranipora lineata, forma lineata part. Smitt, Op. cit. 1867, PI. XX, 

 fig. 26. 

 (PI. XIX, figs. 11, 12, 13, 14). 



The specimens examined diff"er somewhat from those described 

 by Norman, and may perhaps be regarded as belonging to a distinct 

 variety. 



The zooecia are irregularly arranged and the large frontal 

 area is ovate or pearshaped-ovate. It is provided with a well- 

 developed granular cryptocyst and surrounded by 14—20 very long 

 spines curved sligthly inwards at their proximal part; the spines are 

 as a rule fixed in small sinuations of the cryptocyst and slope slightly 

 inwards. They are of very different size, and as a rule the 

 thicker ones are seated in the distal curve of the zooecium, but while 

 in some cases their thickness declines distinctly towards the proximal 

 end, in other zooecia the difference is not so very large. Sometimes, 

 also, one or more very thin ones may appear among much thicker ones. 

 Besides those immediately surrounding the cryptocyst there appear 

 as a rule in the distal half of the zooecium 5— 10 spines placed 

 outside the others at a different height, and sometimes a number 

 of them are seated halfway down the wall. These outer spines are 

 very often very slender. As the cryptocyst has a very variable 

 breadth in different places this circumstance together with the pre- 

 sence of the above mentioned extraordinary spines produces the 

 impression that the spines are more or less irregularly arranged. 

 In a number of colonies from Egedesminde the spines are very much 

 shorter and more are found outside the others. 



I have only seen a single ooecium with an undamaged frontal 

 wall; the latter is densely granular but without other impressions 

 or projections. In the colonies from Egedesminde the ooecium is 

 much larger (its length being contained Vh — 2 times in the length 

 of the membranous area) and more elongate, and its proximal por- 

 tion is provided with a low but broad triangular area. Distally to 

 this area is seen a strong, narrow vertical projection, the surface 

 of which is uneven or irregularly nodulous. It seems to have been 

 formed originally by two lateral halves, representing the thickened 

 margins of the two halves of the calcified ectocyst, which grow 

 together in the median line. It corresponds therefore to the transverse 



