MICRATHEN A. 551 
The vulva is of similar type to that of WV, gracilis, see Plate. Colour variable: dorsal area yellow, with a 
dark brown anterior triangular patch, centrally paler, followed by a similar dark patch, with a very 
distinct small, circular, yellow, central spot; a dull dusky central band runs from this point to meet a 
dark blotch lying between the posterior spines. Lateral and ventral areas dull brown. 
Hab. Mexico, Omilteme, Amula (H. H. Smith), 
6. Micrathena brevipes. (Tab. L. figg. 8, 8a, ¢.) 
Acrosoma brevipes, O. P.-Cambr. Biol. Centr.-Amer., Arachn, Aran. i. p. 62, t. 8. figg. 10, 
10 a-d (g)'; Keyserl. Spinn. Amer., Epeiride, p. 12, t. 1. fige. 9,9a,b (g)*. 
Type, ¢, in coll. Godman & Salvin. Total length 4:5 millim. 
a 
Carapace elongate-oval, with central punctiform fovea and very slight lateral fove. Eye-groups more closely 
situated than in the W. parallela-group. Legs entirely devoid of spines, clothed with fine hairs only. 
Coxa i. without hook, and femur ii. without groove; cox iv. closely situate; leg iii. much smaller than 
the others and isolated, the coxe ili. being remote from those of ii. and iv, Abdomen narrower in front, 
dilate behind. 
Palpal bulb without a serrated lamella, the tibia having a large bifid spur beneath, see Plate. 
Hab. Mexico, Teapa (i. H. Smith); Guaremaua?; Panama, Bugaba (Champion '), 
7. Micrathena obtusospina. (Tab. L. figg. 9, 9 a-7, 2.) 
Acrosoma ohtusospina, Keyserl. Sitzungsber. nat. Ges. Isis, Dresden, 1863, p. 76, t. 2. fig. 9 (2)'; 
Spinn. Amer., Epeiridee, p. 23, t. 1. fig. 20 (2)°. 
Acrosoma armatum, McCook, Amer. Spid. ii. t. 21. figg. 5,5a@(?)°. 
Type, 2, in Mus. Brit. Total length, 2, 14-17 millim. (including posterior spines). 
@. Carapace deeply, broadly, and transversely excavate between the cephalic and thoracic areas. Central 
posterior eyes two diameters, central anteriors one diameter, apart; laterals distinctly separate, about 
three-fourths of a diameter apart. Sternum more distinctly transversely trilobate than in the other 
allied species, having a convex boss opposite the coxz of legs i.-iii. on each side, produced posteriorly 
between coxee iv. into a stout, conical, blunt point, its apex lying between the coxe. Femora of legs 
studded with numerous granules or small tubercles. Tatellw only very slightly dilate behind. F ang- 
groove with four teeth above, three below. 
The vulval scapus has no transverse cavity in front, but is produced into a bluntly rounded tongue of variable 
form, sometimes slightly dilate apically; seen from behind, there lies beneath this scapus a transverse 
oval cavity, into which the lower portion of the scapus descends in the form of an oval plate; on the 
posterior margin of the cavity lies a central convex boss, with a small carinate sclerite on each side. 
The exact form of the vulva is, however, very variable in different examples, 
The abdomen is triangular, with a pair of long, sharp, divergent spines situated less than the length of one 
of them apart, on the anterior third of the median dorsal area, usually directed obliquely forwards. The 
posterior margin is occupied by two long, stout, sharp-pointed spines, one at each angle, divergent, 
directed straight backwards or slightly obliquely upwards, very variable in form, being sometimes much 
longer, and often much shorter, than the dorsal area, in the former case gradually attenuated to a sharp 
point, in the latter abruptly ending in a short point. Immediately in front of the base of these spines, 
on the dorsal side, lies a sharp cusp or spine of very variable length, erect or directed backwards. In 
immature examples a second minute cusp lies midway between these and the dorsal spines, while in those 
still less mature, which are black with white spots, the intermediate lateral spines are slender, sharp, and 
almost as long as the anterior and posterior spines. The chitinous tube is well- -developed, but not so 
long as in M. schreibersi. : 
Hab. Mexico®, Teapa (H. H. Smith); Gutaremata, Chisec (Sarg); Costa Rica 
wh 9 
dyp 2 
