124 Rev. Canon Norman — A Month on 



Vetens.-Akad. Handl. vol. xi. p. 32 (separate copy), pi. vi. figs. 143- 



145* 

 1880. Porina horealis, Hincks, Brit. Polyzoa, p. 229, pi. xxxi. figs. 4-6. 

 1884. Tessarodoma borenle, Busk, Report ' Challenger ' Polyzoa, 



I. Cheilostomata, p. 174, pi. xxiv. fig. 8. 



On the precipices at Rodberg. 



This genus differs from Porina^ d'Orbigny, in having : — 

 (a) ooecia ; {I) avicularia ; (c) a row of large marginal 

 pores ("origelles "). The ooecia, figured by Alder, are very 

 rarely developed — in not one in a dozen specimens could I 

 find them at all ; they are, if present, only to be seen on the 

 very young cells at the extremity of the branches ; they are 

 very small, with a granulated surface, and immediately 

 become wholly immersed and invisible by overgrowth of the 

 surface of the zoariiim, while at the same time the tubular 

 orifice goes on developing and keeps well above the surface. 

 The avicularia also will be seen best on the young cells ; but 

 the presence of these is constant or nearly so. 



With respect to the specific name, it seems to me that 

 the one given by Hars should be used. He first described the 

 species, and Busk, in ignorance of the fact, redescribed it ; 

 both assigned it to a wrong genus : Sars called it a Pustuli- 

 pora^ Busk an Onchopora. Sars was the first to correct his 

 own mistake and Busk's, and, although there was a previous 

 Pustulipor a gracilis^ Milne-Edwards, injustice I think Sars's 

 specific name should be retained . 



Genus Hemicyclopora, gen. no v. 



Zooecia with pores confined to the sides and sometimes 

 anterior portion of front wall. Mouth-opening well arched 

 above, lower margin straight (no denticle within the lip). 

 Reproduction by ooecia, which are imperforated. Xo avicu- 

 laria. No special pore (" fenestrelle "j. 



Type, Hemicyclopora 'polita (Norman). 



11. Hemicyclopora polita (Norman). 



Discopora emucronata, Smitt, (Elvers, iif Koug. \'oteiK-k.-Akad. 



Forhaud. 1871, p. 1129, pi. xxi. figs. 27, 28. 

 Lepralia puliht, liincks, Brit. Pol. p. 315, pi. xxxii. fig. o. 



* Busk questions whether Smitt's " fig. 143 and the lowornioist zoa^cia in 

 tig. 144 really luriu part of Tessarodoinn at all, or have merely become 

 accidentally associaletl with it. Tlie latter tigiires at any rate might well 

 be regarded ii» Lt'pni/i(( [Pariiia) ci/iafa." Certainlv the seniieiivular oral 

 opening is very dit1'i>reiit tVoiu the eiroular form wlneh alway.< prevails in 

 the youngest cells at the extremities of the branches in Tfssarodotna, and 

 tliere are no lateral pores shown in the figures in question. 



