110 



Those corresponding to the fourth and fifth orders of equal width, and 

 continuous from margin to base. First, second, and third orders broader 

 and more exsert at the summit, but thinning out rapidly to a fine point, 

 and terminating at about a fourth from the base, except the primaries at the 

 ends of the major axis which are continuous to the base. Septa, exsert 

 proportionately to the orders in six systems of four cycles. Primaries 

 somewhat high, rounded, narrow, or not projecting much into the fossa. 

 Secondaries apparently only half their height, but all are broken in the 

 only specimen I have seen. Third order a little thinner, but apparently 

 as high. Fourth and fifth orders nearly as thick at the margin, but only 

 very slightly projecting into the fossa as a thin edge ; all highly granular 

 and continuous with the costae. Granules disposed in ridges at the edge 

 of the primaries. Pali small, stylif orm processes before all the cycles 

 except the last. Columella uncertain, as it was partly covered with hard 

 matrix, which could not be removed without destroying the septa. 

 Dimensions — Alt. 4, major axis 4|, 3£. 



Family Oculinid^e. 

 In the third principal group of the Madreporaria aporosa we have 

 the family of the Oculinidce, that is to say, branched corals with lateral 

 buds with a great deal of very compact ivory like tissue. We have two 

 species of this family in the collection — one with alternate calices and a 

 peculiar structure which affords evidence of importance, as I shall notice 

 presently. It belongs to the genus 



Amphhtelia — {Edwards and Haime). , 

 which is erected for dendroid corals with alternate buds. The coenen- 

 chyma is highly developed, especially at the base. The costae are only 

 faintly marked. The columella is rudimentary, or absent, and there are 

 no pali. The septa are few, entire, and not exsert. There are two 

 species living — one in Australia and the other in the Medicerranean. 

 One has been found fossil in our tertiary rocks. This is A. incrustans 

 (Duncan), a very abnormal form. 



Amphihelia striata, n. sp., pi. 1, fig. 4. 

 Corallum of irregular, short, cylindrical branches ; calices circular, 

 scattered, the lower ones sunken, the terminal ones very much exsert, all 

 alternate, very deep and narrowing towards the base. No columella, but 

 filling up from below in an open kind of spongy tissue arising from the 

 coalescence of the septa. In the terminal calices the septa are exsert 

 and salient, in the lower ones they are quite inconspicuous, in six 



