100 
and the surface decorticated. The frontal border is grooved behind, and 
margined by a salient limb. In some respects this cranidium resembles that 
of Saukia pepinensis, Owen sp. 1 
There is also, represented by fig. 26, a stout, falcate genal spine, with part 
of the free cheek, of a form allied to Dikellocephalus or Saukia. It bears a 
close resemblance to the genal spines of forms like Saukia crassimarginata, 
Whitfield 2 and Saukia leucosia, Walcott 3 . 
Fam. Dikellocephalid^:. 
Genus Notasaphus, Gregory. 
Notasaphus fergusoni, Gregory. Plate VII., figs. 27-29. 
Dinesus ida, pars., Etheridge, jun., 1896, Proc. R. Soc. Viet., vol. VIII. 
(N.S.), pt. I., figs. 5, 6. 
Notasaphus fergusoni , Gregory, 1902, Proc. R. Soc. Viet., vol. XV. (N.S.), 
pt. II., p. 155, pi. XXVI., figs. 11-13. 
Observations. —-A comparatively well preserved cranidium occurs in the 
present collection, which I have no hesitation in referring to the above 
species. It is more complete than those figured by Prof. Gregory, and shows 
the large tumid and expanded glabella to be marked with about four faint 
transverse furrows. There is a well marked frontal border present, and the 
neck-ring carries a blunt spine. 
The pygidia of this species are quite abundant in the Heathcote material. 
There is a great variation amongst them, but they cannot be separated into 
any stable sub-species. The spines of the pygidial border vary in number 
from four to six on each side, corresponding to the number of pygidial 
segments. The genus most nearly approaches Dorypyge, Dames, 4 from which 
it differs in the form of the glabella, being more expanded in front. Notasaphus 
is further distinguished in the almost obsolete transverse furrows. Although 
generally held to be Lower and Middle Cambrian, this related genus Dorypyge 
has been regarded by G. F. Matthew and H. Woodward as extending its range 
into the Upper Cambrian 5 . The pygidia of another genus, Black welder ia, 6 
also resemble those of Notasaphus, but in the cephalon of that genus the 
glabella is narrower and tapers anteriorly. 
Super-order Branchiopoda. 
Order Conchostraca. 
Fam. Limnadiid^. 
Genus Lepeditta, Matthew. 
Lepeditta knowsleyensis, Chapman sp. Plate VII., fig. 30. 
(l)Modiolopsis knowsleyensis, Chapman, 1904, Rec. Geol. Surv. Viet., 
vol. I., pt. 3, p. 224, pi. XXI., figs. 11, 12. 
Description.— Valves semi-elliptical, slightly oblique. Hinge-line straight. 
Anterior border rather narrowly rounded and sharply curved backwards 
to meet the dorsal line at an obtuse angle. Ventral margin widely curved, 
rounded at the posterior, and becoming straight near the junction with 
the hinge-line. Surface wrinkled parallel to and near the ventral margin. 
Antero-dorsal area with a compressed border. 
1 See Walcott, Smithsonian Contrib., vol. LVII., No. 13, 1914, p. 381, pi. LXVII.. figs. 1, 4. 5, 7, 8. 
2 Ov- cit., p. 377, pi. LXVI., fig. 3. 
3 Op. at., p. 379, pi. LXVII., fig. 15. 
4 In Richthofen’s “ China,” vol. IV., 1883, p. 28. 
5 H. Woodward. Geol. Mag., 1905, p. 214. 
6 Walcott. Proc. U.S. Nat. Mus., vol. XXX., 1906, p. 573. See also id., Research in China, Carnegie 
Institution publ., No. 54, vol, III., 1913, pp. 116-123, pi. IX., f. 5-7, 
