124 A. £J. VerriU — Bermudian and West Indian Reef Corals. 



Simple young specimens, 20 to 25™™ in diameter, are low, shallow, 

 nearly circular, and usually show no trace of division or lobulation 

 of the margins. They may have five cycles of septa, with the 

 larger ones lacerately toothed as in the adult. Plate xix, fig. 5. 



Tlie radial lobes and collines vary greatly with age ; the most 

 regular young ones, 40 to 65™"' across, usually have six regular, 

 radial calicinal lobes, with six radial collines, and a central primary 

 calicle, but the primary lobes are often five, more rarely four or 

 three. The collines are frequently solid or nearly so, without a 

 groove on top. (PI, xvii, figures 1-3.) 



In ordinary adult specimens the septa are thin, generally rather 

 broad, unequal, and not very close together. The number to a cen- 

 timeter may be eight to twelve, in fully formed calicles, but in 

 imperfectly formed calicles there may be ten to twelve or more. 

 The larger ones are normally thin, but firm, broadly rounded toward 

 the margin, and not very prominent above the wall. But the form 

 varies greatly in different calicles. The serrations are generally 

 numerous, unequal, and mostly rather long, the larger teeth being 

 flat, not very wide at base, and with the tips mostly acute, but some- 

 times forked or lacerate. Those toward the outer ends of the septa 

 are usually decidedly shorter than the inner ones, but they ai*e 

 irregularly larger and smaller on the whole edge. The columella 

 may be rather large and spongy, or it may be small and trabecular 

 or laminose even on the same specimen. 



The costfB are well developed, and like raised, thin ribs, separated 

 by regular grooves, and with the edges sharply and rather regularly 

 serrate, with the teeth very much smaller than those of the septa. 

 Sometimes the costse are sublamellar. They may be confined to a 

 narrow zone close to the edge, or they may be more than 25™™ long, 

 according to the variable extent of the epitheca. 



This species is more apt to have part of the corallites isolated and 

 nearly circular than I. dipsacea. Frequently many of them are dis- 

 united for much of their length. The larger round calicles may 

 sometimes become 40™™ in diameter before the}'^ begin to divide. 



One of our Bermudian specimens has, on one side, a simple, 

 curved, linear valley, five inches long (125™™), containing a row of 

 uniform, united calicles, while on the other side the calicles are 

 partly isolated, and partly in short groups of two or three, and of 

 various forms. 



In the form and colors of the soft parts this species does not differ 

 materially from the last. Its colors are equally variable, but per- 



