
HALE—AUSTRALIAN CUMACEA 361 
joint of endopod with three inner spines, louger than combined lengths of seennd | 
and third, which are subequal in length and have each one inner spine; terminal 
apine two-thirds as long as ramus, extending slightly beyond tip of exopodal 
spine. 
Length 4-1 mm, 
Loc. New South Wales; Ulladulla, Brush Island, 45 fath., in fine silt on flat- 
head grounds (D. Rochford, Jan. 1945). Type in South Australian Museum, 
Reg, No, 0. 2699. 
Genus Grnoprastynis Calman 
Gynodiastylis Calman, 1911, pp, 312, S66; Stehbing, 1912, p. 146 and 1913, p. 
161; Zimmer, 1914, p_187 and 1930, p. 651, 
This genus was instituted by Calman to include four species, in ali of which 
the telson is plump, subeonical, with no post-anal portion and without the pair of 
distinct terminal spines so generally characteristic of the family; in addition, the 
third maxilliped of the females has no exopod, while the males were unique in the 
family in that they lack all trace of the usual two pairs of pleopods. Three of 
Oslman’s species are rather robust in form and haye the carapace carinate; the 
fourth—imevis—is smooth and elongate, with the second and fourth pedigerous 
somites dorsally unusually long. Zimmer (1914, pp, 187, 189, fig. 14-16) added 
two Australian species somewhat resmebling laevis in form, which he designates 
the ‘‘ Diastylopsis-Habitus.’’ The present writer later added another carinate 
species which, like those of Zimmer, agrees with Calman’s forts in having the 
telson unarmed, and alao a smoother species with small telsonic spines, - 
A score of further species—all but one new—are now referred to the genus. 
All the females agree in Jacking an exopod on the third maxilliped, while the 
males, where available, have no pleopods, but a great deal of latitude is allowed 
for the telson; this may have part of its length, as much as fully one-third of it, 
post-anal, and may have a pair of terminal spmes, and in some cases a pair of 
lateral spines also, Its lateral margins may be more or less distinctly serrate, or 
may be incised to form one or more pairs of teeth, a feature found elsewhere in 
the Diastylidae. It would appear, indeed, that the species previously included in 
the genus happen to he some of those in which the reduction of post-anal part and 
armature are carried to the greatest extreme, and that many of them do not depart 
80 drastically from the key character of the family. 
Ag the first of the forms with telson armed and with post-anal portion came 
to hand it was thought that they represented a. genus easily separable from 
Gynodiastylis by this character, With more material, however, it beeame apparent 
that intermediate stages oceur, and that as far as the spines alone are concerned 
there may be some little difference between the aexes (truncatifrons Hale), Pur- 
thermore, obviously related forms of ‘' Diostylopsis-Habitus’’ such as attentuata 
sp. nov, and ambigua sp. nev. have in the one case the telson unarmed and without 
post-anal part, in the other a telson with a small portion of its length post-anal, 
armed with distinct terminal and lateral spinesand with the sides serrate. Exactly 
the same difference may apply to ‘‘carinate’’ forms, for instance /ata sp- nov. and 
ample sp. nav. The telson, then, is of little assistance in the grouping of the 
species. Turning to other characters the first peraeopod proves of some mterest 
and in the key given below the species are divided into two groups by the character 
and length of the setae of the propodus and the relative length of that joint. In 
Calman’s species these differences are found between /agevis and his other three 
forms. It will be noted that in both sections there occur similar differences in the 
telson and similar variations of the '' Drastylopsis-Habitus.”” 
