- 
some Species of Crisia. 471 
rata, sp. n., is 0°16 mm., of C. denticulata 0°11-0°12 mm., of 
C. acropora 0'12 mm., of C. elongata, Waters, 0-14 mm., of 
C. elongata, Harmer, 0°12 mm., of C. conferta, B., 0°18 mm., 
of C. sinelairensis, B., 0°08 mm., of C. sigmoidea, sp. 0., 
0-1 mm., of C. denticulata, var. verdensis, nov., 0°08 mm. 
In the second group the basis rami is long, reaching to the 
next zocecium, as may be seen in C. ramosa, Harm., base 
0:08 mm. wide, C. tubulosa (Cape Verde), 0°1 mm., C. sertu- 
larotdes, Aud., 0°06 mm., C. circincta, Waters, 0°06 mm., 
C. laxa, Busk, 0 O07 mm. . 
In the third group with the “ graft’ basis rami are C. fistu- 
losa, Hell., base 0°11 mm. wide, C, eburnea, Lamx., 0°05 mm., 
C. edwardstana, VOrb., main internode 0°05 mm. wide at 
base, branch internodes 0-04 mm. wide, C. geniculata, M.-Ed., 
0:03 mm., C. cornuta, L., 0°02-0°03 mm. For examining 
the basis rami properly it is necessary to have balsam pre- 
parations, and other points are seen more satisfactorily with 
such slides. 
There is still another character which may give us a little 
assistance, and that is the frequency of the surface-pores. 
The number in a square 0°1 mm. may be counted, but as the 
surface is not flat, and as the zocecial boundary-lines occur 
close together, anything like exactness is out of the question, 
and we must be satisfied with general expressions, and might 
be guided by taking about ten pores to the square (0°1 mm.) 
as few, ten to twenty moderate, over twenty numerous. 
C. eburnea, C. eburneo-denticulata, C. ramosa are few ; CU. 
tubulosa, C, sertularcides, C. laxa are moderate; C. denticu- 
luta, C. sigmoidea are numerous. In the ovicells the pores 
are about twice as numerous as in the zocecia. 
Busk and others have thought they had found elongata, then I’ got a 
form from Wasin (Brit. E. Africa) which seemed to me to be certainly 
C. elongata, and unfortunately, instead of giving it a new name, I placed 
it under elongata, hoping that the difficulties would be laid to rest. 
Since then Harmer ® has found a speties in the ‘ Siboga’ material which 
he considers is the C. elongata, and with this he places the forms described 
by Busk and meas synonyms. With this 1 cannot agree. Naturally, if 
I am right that the species first redescribed as elongata is not the same 
as Harmer’s, then it would seem impossible for the name to be retained 
for the ‘Siboga’ specimens, even if these should only represent one 
species. Certainly we should all have been wiser to have dropped the 
name altogether. 
1 «Mar. Fauna of Brit. East Africa and Zanzibar, Bryozoa,” Proc. 
Zool. Soc. London, 1914, p. 838, pl. i. figs. 3, 4, pl. iv. fig. 6. 
2 « Polyzoa of the ‘Siboga’ Expedition, Ent., Cten., & Cyclost.,” p. 96, 
pl. viii. figs. 1-8 (1915). 
