[ 11 ] 



77. PleiMTocera verrtwosa. Ellipsoidal, top very obtuse, base of the opening ob- 

 tuse, inside lip thickly plaited ; four spires, the two last flattened, the other large, 

 with several rows of warts, back of the opening wrinkled. — Length about -two- 

 thirds of an inch, not quite double the breadth ; colour olivaceous brown, opening 

 whitish. It lives in the lower parts of the Ohio. This genus which contains near- 

 ly twenty species of fluviatile shells, was described in my 70 N. G. Animals, &c. 

 I have discovered already about one hundred and eighty species of fluviatile and 

 land shells in the United States. 



IX CLASS. POLYPIA.— THE POLYPS. 



XIX. N G Megalisma. Body free, globular, cartilagineous, without external 

 organs. A large transversal narrow opening or mouth, Kke a cleft. Inside hol- 

 low, sides covered with undulated, plicated and lobed appendages. — This curious 

 genus belongs to the order Monostomia, family Gymnotremia, and sub-f amify Asom- 

 opia, next to Megastoma, Zocodum, &c. The name means large cleft. 



78. Megalisma maculata Nearly spherical, smooth, brown with black spots. — 

 It was taken on the bank of Newfoundland ; diameter six inches. Moving, roll- 

 ing on itself, contractible, mouth shut or gaping 



79. Millepora moniliformis. Elongate, curved, simple, torulose or beaded ; seg- 

 ments unequal, oval or oblong, rounded, solid ; pores nearly in transverse rows, 

 subequal, suboval or rather approximate. — Fossil, near Lexington. One among 

 the three hundred N. sp. of fossil animals, discovered in Kentucky by Mr. Clifford 

 and myself. 



X CLASS. POROSTOMIA.— THE POROSTOMES. 



XX. N. G. ScALENiUM. Body flat, floating, gelatinous, evanescent, homogen- 

 ous, without organs, unequally triangular. — I have first proposed this last class of 

 animals, which have only invisible pores instead of mouths. This genus belongs 

 to theordeTGymnexia,fa.rmlyAnenata,snh-iatn.i\yAplopsia, nexttoPteropsis, 



80. Scalenimn planum. Flat, leveland/thin, transparent, thethreesidesunequal 

 and straight, angles nearly acute. — In the Atlantic ocean : breadth six inches. 



81. Scalenium. undulatum,. Margin undulated, one side much smaller, sides 

 slightly curved outward, angles obtuse ; colour hyaline, faintly coloured with yel- 

 lowish. — In the Atlantic ocean. 



PLANTS. 



I CLASS. ELTROGYNIA.— THE ELTROGYNES. 



82. Vitis denticulata. Branches and petiols striated and pubescent, petiols sub- 

 equal, leaves reniform, acute, subtrilobe, denticulate, denticules very small and 

 callose, shining above, white tomentose beneath, nerves rufous ; flowers polyga- 

 mous — In the state of New- York. I presented three years ago to the Philosophi- 

 cal Society of N. York a memoir of the Vines of that state, containing ten species, 

 whereof seven were new : this is one of them. 



83. Prunus cuneata. Shrubby, branches straight, round, biangular, leaves cu- 

 neate, obtuse, crenate, base entire, glaucous beneath ; umbels sessile, commonly 

 quadriflore, calix serrulate, rugose transversally. — On the moimtains of Penn- 

 sylvania, probably a Cherry shrub, it rises two feet, branches dark purple, leaves 

 and flowers small, peduncles short, three to five flowers together, white ; it blos- 

 soms in May. 



84. Prunus triflora Arborescent, branches crooked and smooth, leaves sub- 

 sessile, oblong-lanceolate, acuminate, crenate, sub-obtuse ; umbels sessile, com- 

 monly triflore, calix acute, petals arose. — A tree twenty feet high, probably a 

 Cherry tree. In the mountains of Pennsylvania. Flowers numerous, white, 

 smelling strongly of honey. 



85. Rosa pusilla. Stem procumbent, smooth and crooked, stipular thorns 

 straight, petiols pubescent, folioles 3-5, shining above, pubescent and pale be- 

 neath, obovate, oblong, serrate, base entire, flowers solitary, peduncle hispid, 

 stigmas tomentose, umbilicate, fruits smooth, globular, depressed, caKx appendi- 

 culated. — A very small shrub, four to six inches high, fruits rather large, saffron 

 colour. I found it at Button lick in the knob hills of Kentucky. I have sent to 

 Europe the Prodromus of amonography of American Roses, in which thirty-three 

 species and twenty varieties are described, whereof one-half are new. 



