400 PROF. J. A. THOMSOX AXD MR. W. D. UENDKRSOX OX [Apr, 10, 



(c) To C. gracilis May we have referred a colon}' witli pinnules 

 in three rows as May described, and to the same species we have 

 referred another colony with only one row. This seemed at first 

 unjustifiable till we saw that in the colony with three rows in the 

 majority some polyps onl}' showed two rows, while in the colony 

 with one I'ow in the majoiity some showed two rows. 



{d) The total number of pinnules seems to us of more diagnostic 

 importance than the number of i-ows, but in what we believe to 

 be C. garci(e we find in one colony a range from 16-30 pairs. 



(e) Comparisons of different colonies of the same species shov/ 

 that there is little use attaching much importance to the length 

 and breadth of the bare streak on the tentacles unless one is sure 

 that the foi-ms compared ai'e similai-ly pi-esei-ved and in similar 

 states of extension. 



(y") Cases like that which we have for purposes of convenience 

 called C. garcice, var. inermis, lead us to agree with Prof, Hickson 

 that the mere absence of spicules does not make a new species. 



Our general conclusion is that further investigation will show 

 that a number of species of Clavularia should be merged in one, 

 and that at present attention should be paid to the 'tout ensemble ' 

 of characters rather than to any single peculiarity when that is of 

 a quantitative nature. 



These remarks may serve to support our impression that some 

 of the species of Clavularia are in a state of flux, but they 

 may also suggest an inquiry as to the justifiability of adding 

 seven new species to the already lengthy list. The general answer 

 is supplied by the descriptions given ; the charactei'S of the new 

 species seem to exclude the possibility of referring them to any of 

 the species known to us fi-om previous memoirs. 



It may be useful, however, to indicate briefly some of their 

 outstanding features : — 



C. crosslandi has characteristic exceedingly minute spicules like 

 water- worn sand-grains and they are ci-owded in eight longitudinal 

 white ridges. 



C. rejjens is like the well-defined C. inargaritiferce, but has very 

 diflerent spicules — minute capstans and some quadrangular forms 

 with an axial cross, 



C. pulchra has unusually long polyps, tentacles, and pinnules. 



C. zanziharensis has 6-8 rows of wart-like pinnules practically 

 covering the short blunt tentacles, and the colour is peculiar. 



C. mollis has grouped polyps, thread-like pinnules almost 

 covering the tentacles, and an unusual amount of contraction. 



C. parwila has very unusual tentacles with only 9 pinnules on 

 each side, though cei-tainly mature, as the eggs and emljryos show. 



G. pregnans has shoi-t conical pinnules all round the tentacles 

 and a very large genital expansion with embiyos. 



We may also call special attention to the viviparity readily 

 demonstrable in (J. pregnans and also apparent in C. parvula. 



Very noteworthy in some of the species is the profuse abun- 

 dance of zoochlorellse. 



