Anchistylis Hale, 1945

Gerken, Sarah, 2014, Eleven New Species and a New Genus of Diastylidae (Crustacea: Cumacea) from Australia and One New Species from Canada, Records of the Australian Museum 66 (1), pp. 1-62 : 3

Anchistylis Hale, 1945

Type species. Anchistylis waitei ( Hale, 1928)

Diagnosis. Female. Carapace not elongate, with at least 1 oblique lateral ridge curving down towards antennal notch. Pleon slender and short. Maxilliped 3 with exopod. Rudimentary exopods present on pereopods 3–4. Telson without setae. Male. Carapace similar to female. Bases of pereopods 3–5 broad, bases of exopods broadened. Telson with pair of very long terminal setae. With 2 pairs of uniramous or aramous pleopods with specialized setae.

Remarks. The uniramous or aramous pleopods with specialized setae are characteristic for the genus. However, without males, females may be difficult to place in Anchistylis with certainty except by identification to species. Due to the small body size and reduced size of the pleon, when adult or nearly adult males are not present, the genus may be confused with Litogynodiastylis , and can be distinguished by the presence of an exopod on maxilliped 3 in the female (the exopod is absent in all female Gynodiastylidae ). The minimal dimorphism between the males and females is like that found in the Gyndiastylidae, and close inspection of the pleon may be necessary to determine if pleopods are present in subadult male.

Australian species. Anchistylis halei n. sp.; A. longipes Hale, 1945 ; A. similis Hale, 1945 ; A. waitei ( Hale, 1928) .

Key to the Australian species of Anchistylis 1 Carapace with curving dorsolateral ridge and parallel ridge anteriorly ................ A. halei n. sp.

—— Carapace with curving dorsolateral ridge, without parallel ridge ............................................. 2 2 Uropod endopod article 2 longer than article 3 ............................................................. A. waitei

—— Uropod endopod article 2 equal or shorter than article 3 .......................................................... 3 3 Pereopod 1 basis equal to all other articles together .................................................... A. similis

—— Pereopod 1 basis shorter than all other articles together ........................................... A. longipes