214 RECKNT MADREPORARIA OF THE HAWAIIAN ISLANDS AND LAYSAN. 

 14. PORITES SCHAUINSLANDI Studer. 

 Plate LXXXIX, tig. 1. 

 1901. Porites srhauinslandi i^n-DER. Zool. Jahrb., XL, p. 424, p\. xxx, fig. 12. 

 Descriptio».—Froie>i>ior 8tudei-'s description i.s as follow.s: 



Colony incrustiiiK, similar in habitus to P. cribrijjora Dana. It forms a thick lamina, whose upper 

 surface is uneven ami co.nvex, ('(l«cs revolute; consists of a living layer 1 mm. thick, separated by a 

 thin epitheca from the lower dead layens. Five of the.se dead layers could be distinguished. Including 

 them, the corallum is 15 nmi. thick. The width in one direction is 69, in the other 63 mm. 



The upper surface is covered with hexagonal calices, which are separated by distinct walls with 

 acute edges. The usual form of the calices on the convex places is hexagonal. These are the most 

 numerous; the diameter varies between 1.3 and 1.5 mm. Septa 12, falling abruptly into the calicular 

 fossa, but little perforated, witli 4 to 5 similar, rough teeth on the margin and small spinules on the 

 faces. In the bottom of the calice is a small, often only rudimentary columella, surrounded by 3 to 6 

 small pali. Where the upper surface is depres-sed tlie calices are small, 0.6 to I mm. in diameter, 

 deformed in one direction and irregular in outline. In isolated places among the larger calices, are 

 calices 2.5 mm. in diameter, with 6 to 8 pali. The increase in size may indicate that fission occurs 

 along with intercalicular Ijudding. The former may take place by the cutting off of a portion of one of 

 the enlarged calices. 



Places arc seen in which 2 or 3 calices are still connected, without being separated by walls. The 

 dividing walls are first initiated by the fusion of two septa of the elongated calice. 



******** 



Laysan. 



Hemarks. — Professor Studer has also sent uie a photograpli of his t_vpe of this 

 species, but I am unable to make out more detail than he has given in his figures and 

 description. I could not be sure of the septal arrangement. 



15. PORITES LICHEN Dana. 



Plate XC, figs. 2, 2a, 21,. 



1846. Poriles lichen Da.\-.\, Zooph. Wilkes Expl. Exped.. p. 566, pi. lvi, fig. 4. 



Origiftal desa'iption. — Dana's original description was as follows: 



Incrusting, one-eighth of an inch thick, undulate, margin subacute, often flexed upward, and 

 free for a third of an inch; under surface smooth, or obsoletely plicate. Corallum having the cells 

 shallow, and often prominent in minute, thin ridges, which give the surface a reticulate appearance. 



The type is a small specimen, 36 mm. tall, 40 mm. wide, and about 3 mm. thick; 

 on the eminences it is thicker, edge thin. It is eccentrically attached, has a sinuous 

 and crispate margin; upper surface uneven, more or less niammillate; lower surface 

 epithecate, the (pitheca extending to the edge. Beneath the living coral is a dead 

 lamina, which extends almost to the outer edge of the growing portion. 



The calices are shallow, small, from 0.75 to 1.5 mm. in diameter. The smallest 

 calices are in dejjressioiis, the larger ones on convexities of the surface. Several 

 calicinal centers often occur in an elongate series without any hint of a wall between 

 them. (Sec Quelch's '' Napopora;' Chall. Reef Cor., p. 186.) 



The walls present several different aspects. These can best be described l)y 

 beginning with the asexual reproduction in the elongated calices to which reference 

 has been made. In some instances it appears that two opposed septa become length- 

 ened, meet, and fuse, forming two separate calices. In other instances it seems that 



