(FIGS 15–17, 58)

Type material: MEXICO: San Luís Potosí: ♂ holotype and 1 ♀ paratype [CNAN-T0721 and CNAN-T0722 (3.iv.2011; F. Álvarez, D. Candia and R. Monjaraz)], (21°23′30.87″N, 99°0′0.9″W). Municipio Xilitla, Jardín surrealista de Edward James.

Etymology: The specific name is a patronym dedicat- ed to Rodrigo Monjaraz-Ruedas, colleague and friend, collector of the types.

Diagnosis: Sexual dimorphism in scutum shape remarkable (Fig. 15B). Mesotergal areas only with central tubercles present. Central tubercle of areas II and III slightly larger (Fig. 15C). Spines of the ocularium long, very close to each other, fused at their bases (Fig. 16C). Sexual length of femur ratio II: 1.46 and IV: 1.49. Tibia IV slightly swollen in the middle, curved, ventral ornamentation slightly developed (Fig. 16A). Dorsoectal apophyses of coxa IV present, small and not sexually dimorphic. Male genitalia: apical margin slightly convex. Lateral setae cylindrical at the base, flattened distally, basal pair shorter. Ventral microsetae between the distal pair of lateral setae. Two pairs of parastylar setae, basal pair slightly displaced from follis base. Spiniform projections exposed (Fig. 17).

Description: Male holotype: Measurements: scutum length 2.3, maximum scutum width 2.0. Legs. I 1.27/ 0.50/0.85/1.27, II 2.12/0.82/1.90/2.30, III 1.45/0.60/1.25/ 1.47, IV 2.25/0.80/2.10/2.32. Dorsum. Tubercles of dorsal rows present only on areas II–IV, slightly increasing in size backwards, second and third rows with few tubercles, central tubercles slightly larger. Spines of the ocularium larger than ocularium, fused at the bases, and very close to each other (Fig. 16C). Lateral clear areas on scutum projected in triangular shape, lateral clear areas of area V apices and free tergites I and II present, spiniform. Venter. Densely covered with small spiniform tubercles. Coxa IV only with small dorsoectal apophyses. Pedipalps. Patella with two mesodistal spiniform tubercles. Legs. Legs I and II thinner and less ornate than legs III and IV. Legs III and IV covered with numerous spiniform tubercles. Femur III curved. Trochanter III globular, a little bigger than the others. Ventral armature of femur IV noticeably larger, with five to six spiniform tubercles, three basal ones closer between them. Tibia IV curved and swollen in the middle, with two ventral irregular rows of spiniform tubercles (Fig. 16A). Tarsal count 4(2):7(3):6:6. Male genitalia. Apical margin slightly convex. Lateral setae cylindrical, flattened distally, basal pair shorter than the rest and level to the other setae. Two pairs of parastylar setae, basal pair at level of follis base. Spiniform pro- jections exposed, increasing in size apically. Lateral margins of ventral plate slightly concave (Fig. 17). Female paratype: Measurements: scutum length 2.0, maximum scutum width 1.6. Similar to male, with the following differences: scutum slightly subrectangular, sexual proportion of femora to metatarsi: II 1.46/1.49/ 1.80/1.76 and IV 1.55/1.60/1.75/1.49 (Figs 15A, 16A), reduced ventral ornamentation, tibia IV straight and without ventral armature, dorsoectal apophyses of coxa IV reduced, femur IV curved. Tarsal count 4(2):6(3):5– 6:6.

Comparisons: Karos monjarazi sp. nov. and Karos singularis sp. nov. are the only known species with tibia IV in males curved, and with the spines of the ocularium long, close between them and fused at the base. Karos monjarazi sp. nov. differs from Karos singularis sp. nov.

in the scutum shape and the absence of dorsal spiniform apophysis on trochanter II.