Flabellamon turgidulimana (Alcock, 1910)

Brandis, Dirk, 2002, On the taxonomic status and biogeography of the Isolapotamidae Bott, 1970 (Decapoda, Brachyura), Journal of Natural History 36 (11), pp. 1291-1339 : 1313-1314

Flabellamon turgidulimana (Alcock, 1910)

(gure 11a–c)

Potamon (Potamon) turgidulimanus Alcock, 1910: 52 , pl. 3, gure 9.

Ranguna (Ranguna) turgidulimana: Bott, 1970b: 166 , pl. 39, gure 38, pl. 48, gure 33.

Type material. Burma: one, one: USNM 42773, upper Tenasserim , don. Indian Museum ; one: NHM 1909.9.2.2., upper Tenasserim, Indian Museum .

Diagnosis. Carapace smooth, anterolateral margin indistinct, formed only by very small regular teeth, gastric groove deep, connected with indistinct sinuous cervical groove, postorbital crest distinct, not sharp, sinuous, beginning at very small epibranchial tooth leading straight to postfrontal lobes. Chelipeds slightly unequal, chelae rugose, short, cutting edges with large teeth, pleon slender, triangular.

Terminal joint of rst gonopod conical, lateral margin rounded, overlapping zone reaches mesial dorsolateral edge. Terminal joint with a mesial conical protuberance on outer overlapping margin; exible zone strongly elongated with one lobe on lateral side.

Type locality. Upper Tenasserim .

Distribution. Upper Tenasserim.

Measurements. 23.7: 18.9: 8.4: 6.8 ( NHM 1909.9.2 .2).

Remarks. The taxonomic status of this small species has not been discussed since Bott (1970b). The species was described by Alcock (1910) as Potamon (Potamon) turgidulimana , who distinguished the species by the absence of a gap between the external orbital tooth and the lower border of the orbit, and by the degree of expansion of the palm of the larger cheliped. Bott (1970b) used mainly rst gonopod characters and determined this taxon to be Ranguna (Ranguna) turgidulimana , due to the mesial projection of the rst gonopod terminal joint.

Re-examination of the available type specimens here showed that the species can be easily determined by the morphology of the rst gonopod, and that the second gonopod morphology agrees with that of F. turgidula . Both gonopods are dorsoventrally attened and the fused zone of the terminal tube of the second gonopod turns one and a half times round the axis of the terminal tube.