The spermatheca in podotreme crabs (Crustacea, Decapoda, Brachyura, Podotremata) and its phylogenetic implications Author Guinot, Danièle Author Quenette, Gwenaël Histoire naturelle, Département Milieux et Peuplements aquatiques, case postale 53, 61 rue Buffon, F- 75231 Paris cedex 05 (France) guinot @ mnhn. fr guinot@mnhn.fr text Zoosystema 2005 27 2 267 342 journal article 10.5281/zenodo.5397969 1638-9387 5397969 Hypoconcha panamensis Smith, 1869 Female approximately 30 mm wide, Mexico , Cabo San Miguel, CORTES 1 (MNHN-B 20865). FIG. 16. — Hypoconcha panamensis Smith, 1869 , female approximately 30 mm width, Mexico, Cabo San Miguel (MNHN-B 20865); A , thoracic sternum; B , detail of posterior part; C , axial skeleton, not dissected so that spermathecae are not visible. Abbreviations: a , spermathecal aperture; br , transverse bridge; c , crest surrounding spermathecal aperture; cx1 , cx3 , P1, P3 coxae; e4 , e5 , episternites 4, 5; g , female gonopore; i.p. , intertagmal phragma; m , membranous zone separating the flat anterior sternal part from tilted last sternites; 4 , 8 , sternites 4, 8; 7/8 , thoracic sternal suture 7/8. Scale bars: A, C, 4 mm. The thoracic sternum ( Fig. 16A ) is peculiar in that the anterior sternites 4 and 5 form a horizontal plate, sternites 6-8 are bent at right angles and are perpendicular to the preceding ones. The sterno-abdominal depression is located posteriorly. Female sutures 7/8 are relatively short, only present on bent surface of posterior sternites, and end apart. Apertures of spermathecae are located only slightly beyond the level of P3, not very far from female gonopores on P3, and are surrounded by a crest ( Fig. 16B ). The opening is slightly larger than in the Dromiinae and shows as an ovate membranous area. The bulb of the spermatheca is rather large but weakly globular. The chamber has its two sheets that are nearly close to each other, without a marked space between them; the basal thickening is not well marked. A tube is present, although short and relatively narrow, and it is situated laterally; there is a weakly calcified area at the level where it communicates with the exterior.