SYNOPSIS OF GENERA. 
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Favosites, Lamarck (Cours. de Zool. du Mus. d’Hist. Nat. 1812). 
[Type, Favosites alveolata, Lam.] 
Massive or. branching Corals, composed of polygonal or circular cell tubes, 
which are intersected by transverse diaphragms and connected by mural pores, 
and in many species showing twelve longitudinal furrows. 
Examples: Favosites Helderbergice, pis. iv, v and vi. 
Favosites conicus, pi. iii, figs. 4, 6-13. 
Alveolites, Lamarck (Hist. Nat. An. Sans Vert. 1801). 
[Type, Alveolites escharoides, Lam.] 
Corals massive, laminar or rarely branching; composed of compressed cell 
tubes, traversed by longitudinal furrows and intersected by diaphragms. Mural 
pores large, usually situated near the angles of the tubes. Apertures with the 
outer margin projecting. 
Example: Alveolites explanatus, pi. xiii, figs. 15, 16. 
Chaetetes, Fischer (Oryct. du Gouv. Moscou. 1837). 
[Type, Chsetetes radians, Fisch.] 
Corallum growing in hemispheric or globular masses; base covered with an 
epitheca. Cells polygonal, contiguous, intersected by straight diaphragms, 
without interstitial tissue or tubuli. 
With our present knowledge, it seems impossible to separate the forms 
classed with Monotkypa from typical Ciletetes. 
Examples: Chaetetes colliculatus, pi. viii, figs. 1-4. 
Chaetetes monticulatus, pi. viii, figs. 5-7. 
Monotrypa, Nicholson (Pal. Tab. Cor., p. 320. 1879). 
[Type, Chaetetes undulatus, Nicholson.] 
Zoarium growing in irregular hemispherical or globular masses. Surface 
smooth or with monticules of larger cells. Cell tubes contiguous, prismatic, 
thin-walled and intersected by straight diaphragms. No interstitial cells or 
spiniform tubuli. 
Example : Monotrypa ? spinulosa , pi. xvi, fig. 25. 
Monotrypella, Ulrich (Jour. Cin. Soc. Nat. Hist., vol. v. 1882). 
[Type, Monotrypa aequalis, Ulrich.] 
Zoarium ramose, smooth or tuberculated. Cells apparently of but one kind, 
intersected by straight diaphragms. Walls thin, except in the peripheral 
region. 
