Hirsutodynomene McLay, 1999

Mclay, Colin L., 2001, Dynomenidae and Dromiidae (Decapoda, Brachyura) from Guam, Philippine Islands, Tonga and Samoa, Zoosystema 23 (4), pp. 807-856 : 818-819

Genus Hirsutodynomene McLay, 1999

DIAGNOSIS. — Carapace much wider than long, moderately convex, commonly sub-circular. Surface sparsely spinous (especially in antero-branchial region), areolate, and covered with coarse setae, which are short and long, and arranged in tufts. Lateral carapace margin always well-defined and armed with distinct teeth. Frontal groove wellmarked, splits in two posteriorly, cervical, postcervical and branchial grooves usually evident. Frontal carapace margin broadly triangular, continuous, no rostrum or teeth, eyestalks short, eyes protected by well-defined orbits. Female sternal sutures 7/8 end well-apart on low tubercles behind bases of second walking legs.

Antennule can be concealed inside the orbit at the base of the eyestalk. Antennal flagella shorter than carapace width. All segments of antenna moveable, first segment (urinal) always beaked medially and second seg- ment has an exopod firmly fixed. Third maxillipeds opercular, completely covering the buccal cavern, separated at their bases by a plate at the same level as the sternum, basis and ischium of endopod fused but joint always marked by a shallow groove. Crista dentata present. Chelipeds equal, stouter than walking legs, dactyl strongly curved, fingers gaping basally. Last pair of legs very reduced, dactyl rudimentary, forming an obsolete sub-chelate mechanism with an extension of the propodus. Gills usually 19 (including six podobranchs) + seven epipods. Gill structure basically phyllobranchiate but the plates are very variable in shape.

Abdomen of six segments and telson, folded loosely under the thorax, uropods large, abdominal locking mechanism absent. Both sexes have five pairs of pleopods, first pair rudimentary in female, last three pairs vestigial in the male. Male gonopods uniform in structure, first pair consist of a stout, setose semi-rolled tube with an apical plate, second pair needle-like with numerous sub-distal spines, some of which overlap, sinuously arranged around the axis (after McLay 1999).