On the Affinities of Palceozoic Tahulate Corals. 355 



pressa ; apertura latiuscula, brevior quam anfractus ultimus, basi 

 sensim dilatata ; columella brevis, incrassata, baud torta. 

 Long. 1^ mill., diam. |. 



Hah. Persian Gulf, 14 fathoms {Col. Pelly). 



Its minuteness constitutes the principal distinctive character 

 of this species. The tubercle which forms the apex is pro- 

 portionally very large.' 



Planaxis puncto-striatus. B.M. 



P. testa aciiminato-ovata, nitida, alba, lineis spiralibus riifis, partira 

 interruptis (in anfr. ult. circiter 9), cincta ; spira elongata, apice 

 obtuso ; aufract. 6, parum convex!, primi 3 basimque versus 

 transversim sulcati, caeteri crebre puncto-striati ; apertura ovata, 

 alba, spiram sequans ; columella arcuata cum labro callositate 

 juncta ; labrum incrassatum, intus denticulatum ; canalis basalis 

 brevis. 



Long. 7| mill., diam. 3^. 



Hah. Gulf of Suez {M'Andreiv). 



This pretty species may be recognized from any other by 

 the nine transverse red lines and the punctured striae, about 

 twenty in the body-whorl. 



XXXVII. — On the Affinities of Palceozoic Tahulate Corals 

 with Existing Species. By A. E. Veerill.* 



The works of Milne-Edwards and Haime upon corals are so 

 extensive and important, and their classification is so well 

 understood and generally adopted, especially by geologists, 

 that it is of great importance that their errors of classification 

 should be pointed out and fully understood. 



A very unfortunate mistake was made when they instituted 

 the exceedingly heterogeneous and artificial group known as 

 " Madeeporaria Tabulata." This division was based 

 wholly upon a single character of uncertain value, found in 

 certain corals differing very widely among themselves in all 

 other respects. This character, regarded by them as of such 

 fundamental importance, was merely the existence of complete 

 transverse septa or plates across the coral-tubes, or cells, occu- 

 pied by the lower parts of the bodies of the coral-polyps, thus 

 dividing the lower unoccupied portion of these coral-cells into 

 a series of closed chambers, each plate in turn marking a 

 former position of the base of the polyp which occupied the 

 cell, as it grew upward. In most of the other corals, on the 



• Communicated by the Author from the ' American Journal of Science ' 

 for March 1872. 



