27 
casts known as T. nasuta, particularly Mr. Etheridge’s Eig. 2a. The 
specime'i figured there, is however, much worn away on the anterior side, 
and towards the posterior ventral margin. 
Trigonia nasuta {T. mesembria) belongs to that comparatively small 
section possessing a cincture, such as T. gibbosa, J. Sby.,^ T. cUun’miana, De 
Loriol,^ and a few others. In the sudden termination of the concentric 
rugae at the cincture it rcsemhlcs T. dunscombensis, Lycett,^ and T. 
damoniana , IJe Loriol. The nearest ally is without doubt a South Australian 
form named by me T. einctuta, Imt which is less tumid, especially anteriorly, 
possesses a different form of sculpture, and has an almost square posterior 
adductor scar, instead of a transversely elongated one. 
The fragmentary Trigonia lately figured from Mliitc Cliffs by Mr. G. 
Giirich, with a suggested reference to T. Moorei, Lycett, is certainly not that 
species. Lycett’s form is an Oolitic fossil from M^est Australia, with very 
well-marked features of its own quite distinct from those of either of our 
Cretaceous Trigonice. The ’White Cliffs shell is one of two things, either 
T. lineata, Moore, with very broad concentric rugie, or an undescrihed form, 
not hitherto met with in our Lower Cretaceous. I am inclined to the 
former hypothesis, but the specimen figured is too imperfect for satisfactory 
determination. It must not he forgotten that no perfect example of Moore’s 
T. lineata has yet been described. 
Loc. — AVell-sinking on Mount Stuart Ilun, Co. Tongowoko, North- 
"West N. S. Wales { II. OiUiatt). 
ILor. — Lower Cretaceous. 
Colin . — Macleay Museum, University of Sydney. 
Genus — CUCULLAIA, Laniarch, 1801. 
(Syst. Anim. sans A^ertob., 1801, p. 110.) 
CUCULL.EA ? GKADATA, Sp. IIOV. 
(PI lAh Figs. 5 and 0.) 
Sp. Char . — Shell obliquely sub-rhomboidal, much inflated and rugged. 
Cardinal margin short, straight; ventral margins rounded, oblique, especially 
towards the anterior. Anterior ends small, slightly projecting ; posterior 
* Min. Con., 1819, III, t. ‘iSj-oG ; Lycett, Mon. Brit. Foss. Trigonire, 1874, No. 2, t. 18, f. 1 and 2. 
^ Lycett, Mon. Brit. Foss. Trigoni:e, 1874, No. 2, p. 88, t. 21, f. 2-5. 
3 lUd., t 40, f. 5. 
