THE MViiUrODA OF NUUTH AMKUICA. 37 



Tifpr.^r. S. Nat. Mus«Mnn. 



Ilahitiit. — Iii(liiin:i|HiIis, Iiid. 



Ih'MtriptioH n/ tfipr. — Itrowii, Irjjs iiiiW umler purtH paler. SUmhIit, 

 HrjiiTfly iitUMiiiut«Ml siiiU'iiinly. iiH>«l«'nit«'Iy sliiuiiig. First dorsal plate 

 tniiisvrrsi'ly siilMival, tiibrnles l(Ml-H, seta' tipped; laf«Tal margin one- 

 toothed. TiiWerrulation of anterioi se^'iiieiits rather indistiiiet, 4-4-l»; 

 jMisteriorly the first row is more obliterated, tlieKe<'oiid is usually eoiii 

 posi'd of M\ tulierrles, and thosj^ of the last row are aeiiti' and project 

 beyond posterior border of sci;inent; later:d margins three or four 

 toothed. Le^s Ion;;. 



Male: Le«;s stronjjiy erassatt;, last four Joints tnbereulate beneath; 

 eo\a of seeond pair tnneh produced and the end of lolie pitt«'d; femur 

 not mueh swolh'U above; genitalia very sindlar to /'. inronMtnns Lat/el. 



Lenjjth of <? ll.«""", width of first segment 1.1""", width of tenth, 

 l.;j"'"'; 9 lenjrth S..V""', width of tlrst sejrment, S"'"', wi<ltli of tenth 

 scjjment 1"'"'. 



This speeies is very closely related to the I'^uropean PolyibxmitH in 

 vonsfoHH Latzel, as is shown by the tulM-rrnlation and tiie form of male 

 eopniation fo<»t, while it only re.seml)les /'. monU'utris Koch in tuber 

 cnlation. 



I have examincil a male and a female, colle<ted by Mr. Frederick C. 

 Test, my friend and fellow stmlent, for whom th«> s|)e(ies is named. 



6. PolydesmuB bramierl, sp. iiov. 



t f PohitlemnHn peniinfiltitnivitH Korli, Synt. il. Myr., 13.3, iHt" ( I'eiiiiHylvuniii) ; Koch, Die 



MyrioiHMl.il, ii, IS, jil. 6!», tij,', n_'. 1S»W. 



DififinoHtM. — Very similar to I'olffdrxmiis MrrrufnMiiiiy,* but body more 

 di'pressi'd and attenuate anter'orly; antenna' and l<*j;s more slender 

 an<l in the male Icsih crassate. 



Tffpe. — IT. 8. Nat. Museum. 



Hahitat. — Mossy Crec^k, Jefferson C<mnty, Tonu. 



As the characters of /*. xenafus vary exceedin;:fly in respect to size 

 and fonn, I have had considerable trouble in usiug characters exact 

 enough to distinguish /'. hruuueri from the various forms of /*. Hcrratus. 

 Th«' most important ditferences by which /'. hnitnteri is separated from 

 P. nerratuH are those of th*^ male genitalia; but as it is almost impossi- 

 ble to give a good definition of these characters, I have thought it best 

 to say uothiug uow, but wait until 1 can have good figures made. 



Concerning the male g(*nitalia of /*. serratitSy 1 may say that in all 

 the specimens I have examined from Minnesota, Illinois, Indiana, 

 Pennsylvania, and North (hirolina, 1 find that the characters are essen- 

 tially similar, the only important variation being in the number of idate- 

 like spines. I have thought that 1\ branneri may be identical with 



* PohjdesmiiH nciratitH Say, .Fourn. Phila. Acad. Nat. Sci., 106, 1820 =^ P. canadensis 

 New]>ort, Auu. and Majj. Nat. Hist., 205, 1844 (Hudson's Bay) =F. ylaucesena Kooh, 

 Syst. d. Myr., 13:3, 1847 (Xorth America), f P. pennsylvamcm Koch, Syst. d. Myr., 

 133, 1847 (Peuusylvauia). 



