genera, Karsch, 1880

de Armas, Luis F., 2020, Scorpions of Puerto Rico and its satellite islands (Scorpiones: Buthidae, Diplocentridae): an аnnotated list, key for genera, and bibliography, Euscorpius 311, pp. 1-8 : 6

Key for the genera (mainly adult specimens)

1. Pedipalp chelae very robust ( Fig. 2 ). Ventral surface of the pedipalp patella with three trichobothria ( Fig. 3 ). Sternum clearly pentagonal ( Fig. 4 ). Pectines with six to eight teeth ( Fig. 4 ). Leg tarsomere II (telotarsus) with two rows of spine-like setae ( Fig. 5 ). ........................( Diplocentridae ) 2

– Pedipalp chelae feeble ( Fig. 8 ). Ventral surface of the pedipalp patella without trichobothria. Sternum subtriangular to subpentagonal ( Fig. 9 ). Pectines with more than eight teeth ( Figs. 9 , 12-14 ). Leg tarsomere II (telotarsus) without spine-like setae. .............. ( Buthidae ) 3

2. Ventral surface of the metasomal segment V with a distal semicircular area, anteriorly delimited for well-defined transversal carina ( Fig. 6 ). ................................... Cazierius

– Ventral surface of the metasomal segment V without a distal semicircular area, with the transversal carina poorly defined ( Fig. 7 ). ............................................... Heteronebo

3. Pedipalp fixed finger with six rows of denticles, being the basal one very long (it occupies almost the basal one-half of the finger). ...................................................... Isometrus

– Pedipalp fixed finger with more than six rows of denticles, being the basal one very short (it occupies approximately one-eighth of the total length of the finger). ................... 4

4. Pedipalp fingers with inner accessory denticles and accessory outer denticles ( Fig. 10 ). .................................. 5

– Pedipalp fingers without either inner accessory denticles or outer accessory denticles ( Fig. 11 ). ................................. 6

5. Sternite III (the first post-pectinal) with a well-developed pair of longitudinal furrows, which converge towards the anterior part of the plate ( Fig. 9 ). .................. Heteroctenus

– Sternite III (the first post-pectinal) without longitudinal furrows or a feebly submedian pair only. ..... Centruroides

6. Carapace subtriangular. Tergites with at least three welldeveloped longitudinal carinae. Pedipalp fingers with the median rows of denticles not imbricate. .......... Microtityus

– Carapace subrectangular. Tergites with a single longitudinal carina. Pedipalp fingers with the median rows of denticles clearly imbricate ( Fig. 11 ). ........................................ Tityus

Figures

Figures 2−7: Diplocentrid characters. Figures 2, 4, 7. Heteronebo portoricensis, female in vivo habitus (2), coxosternal area (4); metasoma V, ventral aspect (7). Figures 3, 5. Oiclus sp., pedipalp patella, ventral aspect (3); leg IV tarsomere II (5). Figure 6. Cazierius garridoi, metasoma V, ventral aspect.

Figures 8−11. Buthid characters. Figure 8. Tityus obtusus, female in vivo habitus. Figure 9. Heteroctenus abudi, female, coxosternal region and sternite III. Figure 10. Heteroctenus abudi, pedipalp movable finger dentition, showing the median rows of denticles and the accessory denticles (10). Figure 11. Tityus sp., pedipalp movable finger dentition.

Figures 12−14: Microtityus spp., pectines. Figure 12. M. vieques, male holotype, basal middle lamella conspicuously enlarged, modified from Teruel et al. (2015: fig. 2b). Figure 13. M. santosi, female holotype, basal plate and the distal area of the left comb, showing two egg-like organisms firmly attached (outside square), modified from Teruel et al. (2014: fig. 5c). Figure 14. M. borincanus, female holotype, basal plate, modified from Teruel et al. (2014: fig. 2c).