BI'LLETIX 59, UNITED STATES NATIONAL MUSEUM. 95 



compressed, 1 fir 2 inches in breadtli, 3 to 6 thick [sic, ])robably intended to be 0.3 to O.fi] and 3 t<i ^ 

 loiit:. .some with ends verrucose, others scarcely so. The lateral verruca- are jjenerally distant, irrefrnlar, 

 often clonfiated, rising very obliquely, or more or less appresscd to the surface; in other ca.ses small, 

 but little prominent, or even subobsolete, especially belnw. ('ells larpe, those at the summit much 

 crowded, deep, separated by thin walls; the lateral ones mostly circular, not distant, usually with a 

 prominent columella and twelve distinct septa, one of which is wider and joins the columella. 

 Ocnenchyma between the lateral cells not very abundant, the surface thickly covered with very roufih, 

 coarse, spinulo.se grains. 



The largest specimens are more than a foot in diameter. 



Hawaiian Islands, Horace Mann, W. T. Urigham, .1. D. Dana. 



The original description of P. axpera var. hda, is a.s follows: 



One specimen (referred to /'. plimin by Dana) has the branches stouter 0.3 to 0..t of an inch thick, 

 and 1 to 3 inches or more broad, variously jilicate, with the summits lobed and mostly naked, the 

 smaller ones often verrucose, but in the characters of tlie lateral verruc;e and cells it scarcely differs 

 from the large specimens of the ordinary \ariety. The lateral cells, however, generally have the 

 septa less developed, and the surface between them is not so strongly spinulose. But some of the 

 outer branches have the stellate cells and rough surface of the ordinary form. The lateral verruc;e 

 are rather di.stant, not very prominent, very olilitjue, and somewhat appressed to the surface. The 

 naked ends of the branches are covered with large, crowded, deep cells, sei)arated by thin walls. 

 The summits of the branches are separated by quite regular intervals, 0.3 to 0.4 of an inch broad. 

 The sijecimen is about 12 inches broad and 6 high. 



Hawaiian Islands, Rev. Mr. Baldwin, Museum of Yale College. 



The remarks of Professor Verrill on the close relationship between /'. li.galata 

 Dana and P. anpera Verrill have already been quoted. Pi-ofessor Studer expressed 

 the opinion that P. axpera should bo luiited to /'. Jl(iul(tf<i: ho, howo\'(M-, separated 

 them, .saying, "At all events tlie granidations of the ccenenchyma arc coarser, the 

 granules are thick, and with a rough surface in the specimens that I consider P. 

 mpera. " 



I have been able to study the tj'pes of /'. Ii(/uh(ti(, P. (tsjxrn, and /'. HKjhra var. lata 

 in tlie Yale University Museum. There are four specimens belonging to the older 

 United States National Musouni collections; the AUxitroxx ol)taiiiod in XW)'! one sp(>ci 

 men, Plate XVII. tigs. 2, 2", that can lio referred to /'. Hqnlatn. and one. Plate XVI, 

 tigs. 1. \<i, that can lie referred to /'. (/.•<jiri-ii : and Prof. \\ . V. Brigham has sent me 

 nine additional spociin(>ns. two of which arc liguicd. Plates XX, XXI represent two 

 views of a si)ccimcn that can more appropriately t)c [ilaccd in P. VKjuJntii. The stir- 

 fac(> of its coenenchyma is minutely spinulose, the spinules are larger than th >sc of 

 the specimen represented by Plate XVII, fig. 'la, but they arc not so coarse as tlio-c 

 in the specimen represented by Plate XVI, fig. Xa. The second specimen of 

 Professor Brigham's collection, represented by Plates XVI II. XIX. is typical P. 

 anpera var. lata. 



P. Ihjithita and P. as<pera are scparatc(l solely by llic relative coarseness of the 

 crcnenchynial granulations. A careful study of the specimens submitt(>d to me has 

 convinced me that they are not specifically distinct. The width of the branches is 

 variable in l)oth the forms with the Ji<i>ilala and the axpi-ra type of cienenchvmal 

 surface. 



Professor Verrill, in his ledescription of the tj'pe specimen of P. Ii<juhtta, has 

 admirably expre.s.sed the specific charactei's. They consist in the character of the 

 verruca', the well-developed septa and styliform columclhi. and the surface i^ranu 



