1 <;2 Frederick Chapman : 



Genus Cyphaspis, Burmeister. 



Cyphaspis bowningensis, Mitchell. (Plate XIV., Fig. 5 : Plate XVI., 

 Fig. 18). 



Cyphaspis bowningensis, Mitchell, 1888, Proc. Linn. Soc. N.S. 

 Wales, vol. II., 2nd ser., pt. III., p. 418, pi. XVI., fig. 3. Ether- 

 idge, junr., and Mitchell, 1891, Ibid., vol. VIII. , 2nd ser., p. 170, 

 pi. VI., figs. 3, 3a-h; pi. VII., figs. Si-k. 



Observations. — In the Sweet collection from Loyola, near Mans- 

 field, there are two examples of Ci/]jhaspis, somewhat crushed and 

 otherwise distorted. One of these, showing the cephalon and 

 upper part of the thorax, is here figured. At first sight it 

 appears to be distinct from C. bowningensis. on account of its 

 large palpebral lobes, elongate glabella and depressed genal 

 spines. A detailed examination, however, shows that all these 

 differences are due to gentle lateral compression which the 

 carapace has undergone; and a second specimen, still more 

 compressed, confirms this view. As in typical specimens of G. 

 bowningensis, the glabella is distinctly granulate and the pleura 

 characteristically grooved with broad sulci. 



G. bowningensis, or a closely related species, is represented in 

 the Melbournian series by a specimen from South Yarra, consisting 

 of a cephalon with sickle-shaped or incurved genal spines and a few 

 anterior thoracic rings with grooved pleura. The glabella of this 

 specimen is proportionately smaller than any figure of G. bown- 

 ingensis, but this feature is variable amongst the known examples. 



Another probable Melbournian occurrence is that of a diminutive 

 specimen from Whittlesea, measuring only 7.5 mm. in length, as 

 against 12 mm. in a normal specimen. It is rather more elongate 

 in habit than usual, but has not suffered lateral compression, as in 

 the Loyola specimen, since.it occurs in a typical, undisturbed sandy 

 mudstone. The locality of this specimen (Bbl2) is described in the 

 Geological Survey notes as "Hills in township of Whittlesea." 

 This is probably situated on the Whittlesea anticline of Jutson, 1 the 

 i-oeks on which line of strike contain Melbournian fossils, as at Tan 

 Yean to the south. 



Horizon and Occurrence. — Silurian (Yeringian). Loyola, near 

 Mansfield. Presented by Mr. Geo. Sweet, F.G.S 



Also examples probably referable to this species from the Silurian 

 (Melbournian) of South i'arra (coll. by Mr. F. V. Spry); and from 

 Whittles-;, (roll. Geol. Surv. Vie.). 



I Prop. Roy. Soc. Victoria, vol. xx. (n.s.). pt. i.. 1908, p. 213. 



