1896.] ■ SPIBEES FROM THE lOWBE AM4Z01JS. 745 



base of labial plate ; 2nd almost obsolete ; Zrd marginal ; ith 3uh- 

 jnarr/inal. Posterior pair of spinners a little longer than width of 

 sleruum. Carapace quite straight (in profile) behind eyes. Patella 

 and tibia iv. equal to length of carapace. Patella and tibia i. equal 

 to length of carapace. Legs clothed with long hairs ; feathery. 

 Protarsus and tarsi i., ii., iii., and iv. broad, spatuliform. Habits 

 arboreal ; forming silken cylinders under baric of trees or amongst 

 foliage. 



Never having seen the type specimen of M. plumipes, 0. K,, one 

 cannot apeak with absolute confidence as to its generic characters. 

 Specimens of T. sancti-vincenti, Walck., hovrever, agree remarkably 

 with the full figure of M. plumipes and in the arrangement of the 

 eyes which C. Koch has given, and there can be little doubt but 

 that the two forms are congeneric. As distinct from Avicularia, 

 they may be recognized by the anterior eyes forming an almost 

 straight row, whereas in Avicularia they form a strongly pro- 

 curved line. In Avicularia the fourth pair of legs is the longest ; 

 in Tapinauclienius the first and fourth pairs are equal '. Tibia and 

 patella iv. are, in Avicularia, longer than the carapace ; in Tapin- 

 auchenius they are equal to it. The posterior pair of spinners in 

 both these genera are longer than the width of the sternum. 

 Otherwise in general characters the species of these two genera 

 are very much alike ; the anterior row of eyes, however, furnishing 

 the best character — so far as one can judge from the material 

 in hand. 



Mygale sancti-vincenti, Walck., J, Insectes Aptires, i. p.' 216. 

 — Walckenaer says : " La quatriome et la premiere paire de pattes 

 sont presque egales " — " les yeux forment un carre long, transverse, 

 dont la gibbosite est pen prononcee." The generic characters given 

 above of Tapinauchenius have been drawn from specimens of this 

 species. 



Gf. E. Simon, Proc. Zool. Soc. 1891, p. 553. St. Vincent. 



Species probably belonging to this genus hitherto described : — 

 T. latipes, Auss. Verhandlungen zool.-bot. Gesel. 1876, p. 183. 



Venezuela. 



T. reduncus, Karsch, Zeit. gas. Naturwiss. p. 387, vol. liii. 



Costa Eica. 



Of Tapinauchenius, M. Simon says : — " Les moeurs de cea 



' M. Simon in Proc. Zool. Soc. 1891, p. 583, gives the lengths of the first 

 and fourth pairs of legs in T. sancti-vincenti ( J ) as i. 46'2 mm., iv. 48'5 ram. 

 In this measurement the coxa is evidently not included ; if the coxa is included, 

 the lengths of i. and iv. are equal, namely, 59 mm. But of course there is no 

 special value in the absolute lengths ; nor must such chnriioters be held as 

 absolutely reliable. In an Avicularia, (^, n. sp. undoscrihed, for instance, and 

 in A. rutilans, Auss., (J , again, the first pair of legs is equal to, or, if any- 

 thing, slightly longer than, the fourth, instead of vice versd. Wliother this 

 character may ultimately prove to be more than of specific value or not, one 

 would at any rate not regard it of sectional value as M. Simon does (Hist. Nat. 

 Ar. i. p. 133). Many of these characters, however, must only be looked upon 

 as generally true of this or that group and subject to particular exceptions— 

 convenient as guides to classification, but to be used with great caution. 



Proc. Zool. Soc— 1896, No. XLVIII. 48 



