358 Transactions. — Geology. 



preserved than the pectoral arch. The 2^ubes have been 

 crushed notwithstanding that they are strong — about 8mm. 

 in thickness, and with a thickened symphysial margin. The 

 shape is somewhat quadrate, broader than long, shghtly con- 

 cave on its post-axial and slightly convex on its pre-axial 

 margins; tiie shape of the external margin is doubtful. The 

 antero-posterior length of the symphysis pubis is 5-5in., and 

 the greatest transverse width of each bone is 7'5in. The 

 ischmm is strong, and thick in the centre. It is elongated 

 transversely, with concave anterior and posterior margins. 

 The posterior margin projects post-axially at its inner corner. 

 Its antero-posterior length at the inner margin is 6-5in., and 

 in the middle 2-5in. The greatest transverse width is 7'5in. 

 I have attempted a restoration of these bones in PI. XLIL, 

 fig. C. 



No ilium is seen, nor any of the bones of the hind limb. 



EXPLANATION OF PLATE XLIL 



Fig. A. Civioliosaurus caudalis, veutral aspect, reduced to ^ : Jm., 

 humerus ; sc, scapula ; co., coracoid ; p.r., pectoral ribs ; 

 a.r., abdominal ribs ; g.^;., quartz pebbles ; pu., pubis ; is., 

 ischium ; c.v., chevron bones. About one-tenth of natural 

 size. 



Fig. B. Restoration of coracoids. 



Fig. C. Restoration of pubes and ischia. 



Art. XXXIX. — On Conchothyra parasitica. 



By Captain F. W. Hutton, F.E.S. 



[Read before the PUilosophical Institute of Canterbury, 2nd August, 



1S93.] 



Plate XLIII. 



CoNCHOTHYKA PARASITICA is a fossil gdsteropod mollusc highly 

 characteristic of the reptilian beds at the Waipara Eiver, but 

 it has also been found at the Clarence Eiver, at the Malvern 

 Hills, at Broken Eiver, and on the Canterbury Plains near the 

 gorge of the Waimakariri Eiver. It is from this last place 

 that the figured specimens come. 



The name appears first in the Catalogue of the Colonial 

 Museum, Wellington, 1870 (p. 193), and again in Dr. Von 

 Haast's report on the geology of the Waipara district, in 



