168 KECKNT MAOKKPORAKIA of THK HAWAIIAN ISLAND>; AND LAYSAN. 



aiul are laceratelv ilivi.le.l. CVUs thickly scattered over the s^urface, each usually surr.mnded by a 

 cluster of four or live of the larger papilla-, considerably larger than those of the lower side (about 

 0.03 of an inch=0.7o nini.l, with six .|uite distinct septa, which extend about one-fourth across the 

 cells. Toward the central part.'^ of the coral the cells are generally somewhat larger and have 12 

 septa, six verv narrow ones of the second cycle alternating with the six larger primary ones. 



Close to the edge the papilUc sometimes form radiating rows, or unite into short, thin ridges. The 

 largest papilUe are scarcely 0.02 of an inch [0.5 mm.] in diameter, and about 0.04 [1 mm.] in height. 



Hawaiian Islands. Museum of Yale College. Numerous specimens are also in the JMuseum of 

 Comparative Zoology, which were collected by Mr. A. (iarret. 



Hernaid" iilaoc.-; this sju'cics in hi.s tuherculate section of the genus. 



i*rofe.s,sor Verrill has kindly loaned me the type .specimen of this .species, 

 Plate LXV, tigs. 1, 1«, 1/'. Ic. Critical notes on the differences between 21. patula and 

 M. verrilU arc made after the description of the latter species. An additional 

 difference is found in the smaller tubercles on the surface of M. patula. They 

 are much larger and coarser in M. verrill!. 



The tuherculate Montijxrrx of the South Pacitic, 21. incognita Bernard. 2L efusa 

 Dana, etc., are closely related to tho.se from the Hawaiian Islands, and it is not 

 uiilikelv tliat the .same species may occur in both regions. 1 have not been able to 

 study sufficiently large collections to warrant the expression of a positive opinion. 



Profes.sor Studer * identified a specimen from Laysan as doubtfully V)elonging to 

 2f. patuhi. It probably is a different species. An illustration of it, from a photo- 

 graph furnished by Professor Studer, is given on Plate LI, tig. 2. 



8. MONTIPORA VERRILLI, new species. 

 I'late bXIII, tigs. 2, 2o, 1h; Plate L.KIV, figs. 1, ^a. 



Corallum incrusting an irregular surface, completely attached up to the edge on 

 one side, on the other side the edge projects nearly ?.n mm. beyond the attached 

 portion, (jreatest distance across colony liT mm.; least. lUo mm. Edges thin or 

 rather thick, near the center the thickness may exceed 20 mm. The upper surface 

 thrown into hillocks with valleys between, following the irregularities of the surface 

 to which it is attached. 



Where the corrallum is projecting and free, calices occur on the underside, 

 further within, however, there appears to be a basal epitheca. The lower surface of 

 the free portion is almost even, with the mouths of tiie calices approximately level 

 with the ccenenchyma, sometimes slightly elevated, small, 0.3 to 0.6 mm. in diameter, 

 and distant from once to twit'e their diameter. Even in these very .small calices two 

 complete cycles of .septa are often present. Here the ornamentation of the ccenenchyma 

 consists of small, sim{)le spines, prolongations of the reticular trabecula?. On the 

 upper surface there are two kinds of t'alices, not elevated and elevated, in some 

 instances raised as nuuh as 3 nun., of all heights between (i and 3 mm. Not 

 infretjuently two or more calices may project in a bunch, making the surface very 

 uneven. The free portion of the walls of the projecting calices is polygonal in 

 cross section, often pentagonal; it is very rough and more or less spongy. The 

 elevated calices are from 0.7 to 0.9 mm. in diameter; the lower ones from 0.4 to 0.6. 



"Cat. Madreporarian Cor. Krit. Mus., Ill, 1897, p. 144. 

 ''Zool. Jahrb., XL, p. 420, pi. x.x.x, fig. 1,3. 



