212 RECKNT MADREPOKAKIA OK THK HAWAIIAN ISLANDS AND LAYSAN. 



the triplet. Vsuialioii from this sclienif is rare. Between the palar ring- and the outer 

 edge of the calice are two or three small i)ut i)roiuin(>nt, irregularly shaped, I'ough 

 dentations; two is the usual luanher of septal trahecula\ The septa are thick, espe- 

 cially (listally; th(>ir inner (>nds also are thickened and fuse rather solidly around the 

 columella. The septal fai-es are rough, with sevei-al comparatively large granulations 

 on each. The interseptal loculi arc narrow. In some instance the thickening of the 

 .septa and the enlai-gement of the lateral gi-aiuilations may almost obliterate them. 



Columella terminated hy a small. comi)ressed tubercle. The fossa around the 

 tubercle is very siiailow. i. e. , the columella is not sunken. The thickening and fusion 

 of the inner ends of the sejjta have been described. 



Z«6'(///Vy. — A uau Channel, between Maui and Lanai islands. Station 3876; depth, 

 28 to 43 fathoms; bottom, sand, gravel; temperature, 74'^ F; ?> specimens. 



Ootype-s.— Cut. No. 20820, U.S.N. M. 



Reniarhs. — This species occurs along with P. studerl, but tliej' are strikingly 

 difl'erent; the most noticcal)le ditierence is in their form and the relative depths of 

 their calices. The nean^st relative of /*. hernnnJi seems to be P. lanuginosa Studer 

 from Laysan. 



According to Professor Studer P. lanuginosa differs in habitus, and '"the calices 

 are * * * clearly separated one from another by loose reticular walls." From 

 his figure the calic(>s aie shallow but not su))orticial. The surface of P. hernanli is 

 ver\'. rough, and because of X'w many small spines looks woolly, as Professor Studer 

 says is the casi> in his species. 



12. PORITES TENUIS Verrill. 



Plate XC, tig.'*. 1, la. 



ISbti. Poritea tenvis Vekrill, Proc. Essex lust., V, p. 25. 



1886. ? Porile.1 ti'iiuU {j)iiii) Quelcii, Reef Corals, Challenger Kept., p. 184. 



^'errill originally ga\e "Loo Choo Islands?" as the locality whence this species 

 was obtained. tinelcli subse(|uently reported it from Honolulu. Verrill's type 

 is in the United States National .Museum. Cat. No. 407. U.S. N.M., North Pacific 

 Exploring Kxpedition. The following description is based upon this specimen: 



Corallum subs))heri( al. surface somewhat glomerate. Greater diameter. <!3 mm., 

 lesser, 54. 



Calices shallow, polygonal, small, about 1..') nnu. in diameter, or slightlv less, in 

 depressions .sometimes not over 1 mm. Wall thin, usually continuous, zigzag; 

 however, it is often discomiected and imperfect. Septal arrangement shown in the 

 enlarged view of the calices. The lateral septa of the triplet fuse to the sidi-s of the 

 ventral directive. The four jjrincipal pali are present, and also one on the ventral 

 directive. Uatlier often a smaller pains is on the end of the dorsal directive. The 

 pali are comparatively large and tall, and show small granulations. Usually there 

 are two synapticnlar rings wTthin the wall, one near th(> wall, the other surrounds 

 the columella tangle. There are about three, or may be one or two more, minute 

 denticles on the septal margins between the pali and their uiipiM-most edge; as a rule 

 one, occasionally two, septal traiiec^uhe and a similar muuber of septal granules. 

 The colimiella consists of a compressed tub(>rcle lying between, and in the plane of. 

 the two directive .septa. The septal ends, lying within the inner .synapticular ring, 



