[»' ] 
77. P!eitrocera verrucosa. Ellipsoidal, top very obtuse, base of the oppnins-- ob- 
t^S( , inside lip iliickK plaited; four spires, the twc, l:st fiattLiied, ti ; oti.- > ..ig'', 
Willi several rows of warts, back of the opening wriiikU d.- I,eiigth ab u' wo- 
thirds of an inch, not quite double the breadili ; Colour olivaceous lirown. >,[>. f, '.g 
whitisii. It lives in the lower parts of the t)hio. i'his s^euus v\hi(h coiii;i iis iitar- 
ly twenty species of fldviaiile shells, was described in my 70 N. G. Am;' ids, &.c. 
I have discovered already- about one hundred and eighty species of fluviatiie aiid 
land shells in the United States. 
IX (L \SS. POLYFIA — THi: POLYPS. 
XIX. N G M.:iiA isMA. Body free, globular, cartliaguu;i us, without external 
organs. .\ large trai.svcrsiil iiarrow opening or mouth, likca cleft. liiside hol- 
low, sides covered with undulated, plicati-d and lobed appendages— This cuiious 
genus belorigs to the <n\\cr .Moiiostomia, family Gijmiiotve^nia. and sub-family .isnu- 
opia, next to Mfuast'ima Z'icoiht7n,&c. The nami^ means large clefi. 
rS Ale^alisma macvlata early spherical, sm'.oth, •brown w it'll black spots. — 
I; was taken on the bank of Newfoundland ; diameter six inches. Moving, roll- 
ing on itself, coiiiracti'.dc mouth shut or gaping • 
79. nMillffmratnonitfiimis. Elongate, ( urved simple, torulose or beaded ; seg- 
ments unequal, oval or obloig, rouiulea, solid ; pores nearly in transverse r;)\\ s, 
subequal, suboval an.l rath -r approxiiraate — Fossil, near Lexington. One among 
t-he three hundred N. sp. of fossil animals, discovered in Kentucky by .Mr. ClifFurd 
and m\ self 
X CL\SS POROSTOVIlA.— rilE POUOSTOMES. 
XX V G. S.' vi.emhj-*!. l5o;i\' Hit, floating, geiat:nous. cvane.sctnt, homogen- 
ous, without organs, unequally triangular. — I li.;vc first proposed tlils last class of 
animals, which have oiiiy invisible pores instead of mov.ths This genus belo-^s 
to the order Gvmnexia fa:iiil\ .Jnendiu, sub family .Ijil-pd i, next to I'teropa: , 
8U Scatei.inm rlaniiy.i. Flat, Kvel and thin, tiansparent, the three suit s ui'^q^l 
and stiaight, a igies m arly acute. — In the Atlantic ocean : breadth six inclu-s. 
81. Scalctiinm niuhdatum. .Margin undulated, one side much smaller, sides 
slightly carved outward, angles obtuse ; colour liyahiie, faintly coloured with yel- 
lowish. — In the Atlantic ocean. 
PLAN i 8. 
1 CLASS. FL TROGYNLV.— i HE ELTROGYNES. 
82. Vitia den'iculata. Branches and petiols striated and jnibescent, petic.ls sub- 
equal, leaves reniform, acute, sublrilobe, denticulate, denticides very small and 
callose, shining above, white tomentose beneath, nerves rufous ; flowers pdxga- 
mous — In the state of New-York. I presented three years ago to the Fhilosoplii- 
ivi\ Society of N. York a memoir of the Vires of that state, conlai;Jng ten species, 
whereif seven were new : this is one ol them. 
83. Pninns atneala Shrubby, branches straight, round, biangular, leaves cu- 
neate, obtuse, crenate, base entire, glaucous beneath ; umbels s;.ssile, cotnmonly 
quadriflore, callx serrulate, rugose transversally — On the moiuitains of Penn- 
sylvania, probably a Cherry shrub, it rises two feet, branches dark purple, leavea 
and flowers small, peduncles short, three to five flowers together, white ; it blos- 
soms in May. 
84. Prnnns trijlora. Arbor'^scent, branches crooked and stiiooth, leaves sub- 
sessile, ohlong-lanceolate, acuminate, crenate, sub. obtuse ; umbels sessile, com- 
monly triflore, calix acute, petals erose — .\ tree twenty feet high, probably a 
Cheiry 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 i)ubescent, 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, calix appendi- 
culated. — A very small shrub, four to six inches high, fruits rather large, satF'-on 
colour. I found it at Butt(m lick in the knob hills of Kentucky. I have sent to 
Europe the Prodromus of a nmnography of .\ni. rica Tioses, in which thirty-three 
species and twenty varieties are described, whereof one-half are new. 
