9 
to a cycle. The great value of Nicholson’s observations lay in his confirmation 
of Lindstrom’s previously expressed opinion, that “each colony of the typical 
II. catenularia, Linn., consisted of two structurally and functionally distinct 
sets of zooids,” and in a general way of Eischer-Benzon’s researches also. 
The morphological structure of Saly sites is fully entered into by Nicholson 
in his usually clear and lucid style, and his conclusions were briefly as 
follows : — (a) The epitheca and corallite walls are continuous, and the former 
docs not take any part in the formation of the transverse walls ; (b) the 
partitions between corallitcs are formed by their coalesced walls solely ; 
(c) corallites arc of one or two orders, as the case may be, normal corallites 
and interstitial tubes ; (d) when both are present, the tabulae of the former 
arc complete, and those of the latter sometimes vesicular ; (e) the normal 
corallites may or may not be septate; (/) the interstitial tubes sometimes 
appear to possess modified septa ; (g) the septa are spiniform, arranged in 
vertical rows, and twelve in a cycle. 
1883. — Lindstrom(G.). 1 — In a Chinese coral referred to H. catenularius, 
Linn., Lindstrom described twelve short thick septa in the autopores, simple 
tabulae, and solid inter-autoporal walls. 
1883. — Roemer (E.). 2 — This eminent Palaeontologist accepted Eischer- 
Benzon’s views as to the existence of a false columella in some species. He 
described H. catenularia , Linn., with twelve septa extending to near the 
centre of the corallites, and close and horizontal tabulae ; intermediate tubes 
(mesopores) sometimes present with similar tabulae. II. escharoides, Lamk., 
is distinguished only by the less size of its corallites, and a smaller number in 
a chain. 
1890. — Steinmann (G.). 3 — Gives figures and a brief description of 
II. catenularia, Linn. His illustration of the transverse section is copied 
from Eischer-Benzon’s figure of II. cavernosa, E.-B., with all its peculiarities. 
In the longitudinal section complete and incomplete tabulae arc seen in the 
autopores, and complete in the mesopores. 
1894. — Weissermel (W.). 4 — -Refers to II. catenularia, Linn., as “this 
easily distinguishable form” ! Between every pair of large corallites (auto- 
pores) occur one or two small tubes (mesopores), but septa are absent in tbe 
1 Lindstrom, Beitrage Pal. China (Richthofen’s China, IV), 1S83, p. 60. 
2 Roemer, Lethasa Pal., 2 Lief., 1883, p. 486. 
3 Steinmann, Elemente Pal., 1890, p. 109, f. 111. 
4 Weissermel, Zeit. Deutschen Geol. Gesellsch., XLVI, 3 Heft, 1894, p. 661. 
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