CORALS OF THE CINCINNATI GROUP. 195 



Ch.etetes pulchellus, Edwards and Ilaime. 



Plate 21, figs. 5, oa. 



Chxtetes pulchellus, Edwards and Haime; Pol. Foss. des Terr. Pal., p. 271. 

 Montindipora pulcheUd, Ibid; Brit. Foss. Corals, p. 267, pi. 62, %. 5. 



rorallum very variable in form, usually of sub-cylindrical or com- 

 pressed branches, which have a diameter of from two to six lines, some- 

 times forming flattened, expanded, and sub-palmate stems, sometimes 

 inosculating and reticulated. Corallites thin-walled, polygonal, unequal 

 in size, the ordinary ones averaging about eight in the space of one line. 

 Surface exhibiting rounded or somewhat stellate groups of large sized 

 corallites, which are usually almost twice as large as the average, two or 

 three occupying the space of half a line, and which sometimes have 

 very minute cylindrical corallites interspersed between them. These 

 groups of larger corallites generally comprise from five to seven or more 

 individuals, and they are generally very slightly elevated above the gen- 

 eral surface, so that any tuberosities which may exist are slight, rounded, 

 and inconspicuous. Usually the groups of large corallites are placed at 

 distances apart of about one line. 



The t^'pical examples of C. pulchellus, E. and H., can be very readily 

 recognized by the well marked groups of large sized corallites inter- 

 spersed amongst those of average size, the groups often being slightly 

 elevated above the general surface, but not occupying conspicuous 

 tubercles. Moreover, the corallites are thin-walled, usually hexagonal, 

 and rarely exhibiting any very minute intercalated tubuli. Never- 

 theless, C. pulchellus affords an excellent instance of the enormous diffi- 

 culty which the observer has to encounter when he examines an exten- 

 sive suite of specimens of these corals, and would endeavor to separate 

 one form from others nearly allied to it. So great is this difficulty that 

 it must be understood that no absolute assertion is made by me as to the 

 real distinctness of some of the forms here described under distinct 

 names. I have had the opportunity of examining very extensive col- 

 lections of these corals, and have been enabled to separate certain ex- 

 amples which present characters sufficiently distinct to be recognized 

 v\dth()ut difficulty by the practiced observer, but I am far from asserting 

 that still more extensive collections might not show a graduated series 

 of intermediate forms uniting the several apparently distinct types with 

 one another. As regards 0. pulchellus, at any rate, it is certain that, 

 whilst type specimens of the species can be recognized without the 



