.\i:.\( HNIDES ARANEIDES ORBITELAR] 1 77 



tional iiiteiv-t M their discovery. Tin- species arc spread all over tin- 

 in li.itli tempi-rate and torrid region-. November, isSl.) 



At Ai\. (Joiinvt found lint a single member of this t';uuil\, which In- 

 ivli-i T'-d In a distinct LM-nus called < 'ercidiella. 



TETRAGNATHA Latreille. 



Tliis ^eiiu> lias never l.efoiv l>een recc >M i li/ed in a fossil state. Although 

 repre.-ented iii every continent. it is only in America and particular] v in the 

 warmer parts of North America that it is at all abundant: here some species 



8 north to Neu Knidand. Imt it is essential!} a ^-enus of the Southern 



States; tlli-->- .-piders tVi-|llellt tile Ili.rdtT- of ponds and llelice it is Hot 



strange that \\>- should find them in the lake deposit-, ,,f Florissant, although 

 their piv-i-m-1- iln-ri- certainly indic.it.-> a uarnn-r climate than the present. 

 Phe Species here de>crihed doe> imt appeal- to ha\'e special ailinities with 

 the American specie- \\ith which I ha\e heeii alile to i-ompare it, lieiii- 

 stouter liodied than th-'\ . i N'ovemlier, 1 x ^l. 



'l'i: i i: \ii\.\ m \ i i i; i I AIM \. 

 I 'I. II, FI-. 1 i ' 



: in. ll> .1. I'.il.-i.ni., I, ii. 7 I I. I ..; '.: I- 



\ -in^-le male and its reverse 1'6] tin- under surface ot' this spe- 



cie-: as pre-er\ed, it i- of a pale rn-l\ color, the cephalot horacic append- 

 :c^<-< much darker than the alidoiin-n. which is a- pale as the le^s, or than 

 the cephalothorax, which is m-arly as pah-. Tin- cephalolhorax is circular 

 or scarcely longitudinally oval, the exposed \entral portion lietueeii the 

 - of the mandibles and le^s shield-shaped or heart-shaped. The man- 

 dililes are verv lar^e, longer than tin- cephalothorax, liroadi r on the apical 

 than on the lia-al half and thus formed of t\\ o part.-, a basal, Straight, equal 

 piece, as broad as the third or fourth legs and alint donl.l.- tin.- length of 



the COXSB, and an apical ovate portion, not unlike the apical joint of the 

 pal|ii, somewhat longer than tin- lia-al portion and fully half as liroad_ again 

 as the front'li-- l'..'\ ond ihese. and separated from Them liy a little space, 

 and therefore supported In a lon^ pedicel, which howe\er is not piv>er\ i-d, 

 are the apical palpal joints, a little smaller than the apical portion of the 

 mandibles and of almnt tin- sann- shape, in the interior of which a strongly 

 curved corneous thread can be made OUt, forming more than a complete 



