Art. XIII. — ^4 JJescrvptioii of Omrnatocarcinus corio- 

 ensis, Crc'.sswcU sp., from tlie Lotver Tertiary of 

 Vict or id. 



By T. 8. HALL, M.A., 



Universitj' of Melbourne. 



(With Plate XXIII.). 



[Eead Stli September, 1904]. 



Durins a recent visit to Port Campbell I gathered a number 

 of specimens of a fossil crab which turned out to be the only 

 described species found in our Tertiaries. and, as the original 

 description is not very precise, and is not accompanied by a 

 figure, I thought it as well to supply the deficiencies, as till I 

 saw Mr. Cresswell's specimens I could not be certain of their 

 specific identity. 



Ommatocarcinus corioensis, Ctesswell sp. 



Gonoplax corioensis, Cresswell. Victorian Naturalist, vol. 3, 

 1886, p. 86. 



CarajDace, nearly twice as broad as long. Front almost 

 straight, being but slightly hollowed on each side of a median 

 convexity. Interocular region three-fourths the width of the 

 front and equal to the length of the antero-lateral spine. The 

 spine when resting on the merus of the chelate limb reaches to 

 its own length from the distal end of the nierus. Lateral edges 

 of the carapace converging posteriorly, the postero-lateral angles 

 rounded. Hind-edge as long as the distance of the transverse 

 ridge from it. This strong transverse ridge runs across the 

 whole width of the carapace, a.nd is slightly bent backwards 

 near its ends, where it forms a small rounded projection on 

 the lateral edge at about the length of the anteru-lateral spine 

 behind its base. The ridge is about one-third of the length of 

 the carapace from the anterior bordei", and parallel to it. 



