128 PEOF. p. MAEXIN DTJNCAN's EEVISION 01" THE 



Haime as a unique genus or a group of Pseudo-Fungidse, because 

 of tlie Affaricia-like appearance and perforated wall. Dana 

 placed the genus in tlie Astrseidse, and I think that is its proper 

 position ; for the perforations are not more than growth-apertures 

 and do not always exist; and informs where there are calices on 

 both sides of the common wall there are no perforations. I do 

 not retain the group Pseudo-Fungidse in the sense of M.-Edwards 

 and Haime. 



Group-Genus Merulina. 



G-enus MEEULrRA, Ehrenberg, Oorall. des Both. Meer. p. 104 

 (1834), amended. 



Colony fixed, foliaceous, frondiform, folded, or subdendroid. 

 Corallites in linear series with fused walls, having simple ridges 

 crossed by septo-costse. Calices with centres distinct, in small 

 series, confluent by their septo-costse. Columella slightly deve- 

 loped, spongy or tubercular. Septa stout, sharply denticulate, 

 trabeculate, here and there few, granular at the sides. Common 

 plateau, when it exists, is striate and echinulate along long and 

 somewhat diverging lines, bound as it were in long groups, 

 between which are perfect foramina near the edge of the colony, 

 and deep depressions like slits elsewhere. Where the colony is 

 not foliaceous and is solid, there is no common plateau, and there 

 are no perforations, the calices being on all sides. Endotheca 

 scanty, often only seen at the columella. Gremmation sub- 

 marginal and calicinal. 



Distribution. — Becent. Indo-Paeific, Pacific Ocean. 



XIII. Alliance PLERASTR^OIDA. 



Agglomerate Astrseidse increasing by calicular or extra-calicular gemma- 

 tion. Septo-costse confluent. Dissepiments present. No synapticula. 

 Septa denticulate and entire. 



Genus Plbrastk^a, Ed. & H. 



Genus Holoccenia, Ed. & H. 



There is some difficulty in placing the next genus, Plerastrcea, 

 in its proper classificatory position. According to Milne- 

 Edwards and Jules Haime its position is next to the genus 

 Olausastrcea, d'Orb., in the Astrseidse. But in a species I 

 described from the Eocene of Sind I found synapticula. By a 

 printer's error this form has been termed Pterastrcea.) The 

 figure given by Milne-Edwards and Jules Haime in the Ann. 

 des Sci. Nat. 3® ser. t. x. pi. 9. fig. 12, leaves no doubt about the 



