11 
autopores, with very close-set “ coalescent ” or vesicular tabulae, those of the 
autopores being “ comparatively regular and distant this vesicular structure 
again indicates a departure towards II. cavernosa , F.-B. ; there are no spini- 
form septa. Var. nitida, Lambe, possesses septa in the autopores and 
mesopores, with very compact, regular, and horizontal or slightly concave 
tabulae in both. 
If Mr. Lambe is correct in referring these diverse forms of structure 
to the typical H. catenularius, Linn., as varieties, and I say “if” without 
the slightest wish to impugn the accuracy of his determinations, then it 
certainly seals the fate of Nicholson’s suggested method of distinguishing 
between the two supposed type species. For my own part I much prefer to 
regard Lambe’s varieties as separate species. 
1902. — Pocta (P.). 1 — The observations of this author, one of the most 
recent writers on Haly sites, are of importance. Ilis study of the Bohemian 
corals leads him to conclude that only two species are 'well-defined — the two 
typical forms of Milne-Edwards and Haime. He unhesitatingly accepts 
Nicholson’s method of separating them, and states that the spiniform septa 
vary from twelve to fifteen, but the coral with zooids of two orders 
(R. catenularius, Linn.), rarely possesses them. Mr. Pocta is unable to 
confirm Fischer-Benzon’s description of vesicular tabulae in Halysites from 
personal observation, but he records a new and very important feature in 
II. escharoides, the closing of the autopores by oval, concentrically-striated 
opercula, probably the uppermost tabulae, as in some Favosites. 
1 Pocta, Barrande’s Syst. Sil. Boheme, VIII (ii), 1902, pp. 272-275. 
