GENERAL HISTORY. 21 



poroids, I should still think it expedient to create a new name 

 for the division. As it is, however, the forms included by 

 Dybowski under the head of Diaimliies, Eichw., appear to me 

 to be of different affinities, as regards some of them at any rate, 

 while the asserted absence of a " coenenchyma " {i.e., of inter- 

 stitial tubes) is certainly not true of them all. Thus, Monti- 

 ctdipora petropolitana, Pand., included by Dybowski under the 

 genus Diamilites, possesses a " coenenchyma " in the same sense 

 that any Monticuliporoid can be said to do so — that is to say, 

 it possesses a series of small interstitial corallites, which are per- 

 ceptibly, if only slightly, more closely tabulate than is the case 

 with the larcfe ones. That these interstitial corallites are fewer 

 and more scattered than is usually the case in the Monticuli- 

 poroids, does not alter their morphological significance, and 

 would not justify us in excluding them from the category of 

 what Dybowski calls " Ccenenchym." In addition to M. petro- 

 politana, Pand., Dybowski places under Diaimlites, Eichw., 

 seven species or varieties — viz., D. peti^opolitanus, van hcxa- 

 porites^ Pand., D. apictilatus, Eichw., D. rhovibicus, Nich., D. 

 eleganhihis, Fr. Schmidt, D. Haydenii, Dyb., and D. siilcatiis, 

 Dyb. Not having seen any of the original examples upon which 

 these species are founded, I can, of course, say little about them. 

 Judging, however, from the descriptions and figures given by 

 Dybowski, I should say \kvaX D . fastigiatus, Eichw. { = D. detri- 

 tus, Eichw., according to Dybowski), is even nearer to the 

 type of M. petj'opolitana, Pand., than the form to which Dy- 

 bowski assigns the latter specific name. D. petropolitanus, 

 var. Jicxaporitcs, Pand., would seem to be a separate species, 

 and not a mere variety of M. petropolitana. D. apiculatiis, 

 Eichw., is a peculiar type, which is more clearly dimorphic than 

 is even the case in M. peti'opoiitana, Pand. The form termed 

 D. rJwmbicus, Nich., is not sufficiently figured, but has nothing 

 to do with the form which I described under the name of CJice- 

 tetes rhovibicus, and which is really identical with the M. quad- 

 rata of Rominger. The D. elegantuhts, Fr. Schmidt, has 

 obviously no relation with any of the preceding. It, also, is 



