380 MAZATLAN UNIVALVES 



FAMILY CAJSTCELLAEIAD^E. 

 GENUS CANCELLAEIA, Lam. 



j 445. CANCELLARIA UECEOLATA, Hinds. 



Proc. Zool. Soc. 1843, p. 47 : Voy. Sulph. Mollly. 41, no. 171, 

 pi. 12, f. 7, 8. Sow. TJies. Conch, p. 443, no. 13, pi. 94, f, 48. 



Cancellaria obesa, P. P. C. Cat. Prov. ; non Sow. 



? = Cancellaria ovata, Mice, in Zeit.f. Mai. 1850, p. 181, no 51 ; 

 non Sow. 



The character by which Mr. Hinds distinguishes this species, 

 that the nail is not obstructed when drawn in the direction of 

 the axis, is by no means constant. There was considerable 

 variation in about 50 specimens examined. Shell sometimes 

 with spire depressed, resembling C. obesa ; sometimes very 

 prominent. Cancellations cose and conspicuous on the early 

 whirls, (the first 3 being smooth, deciduous,) afterwards very 

 variable. Two sp. of nearly the same size have the ribs two to 

 one. Spiral lines more or less expressed. The plaits have a 

 slight callus below, near the termination of each, giving them in 

 some positions a sub-bifid appearance. Sometimes there is a 

 slight parietal tubercle. Labrum with 8-10 lirse inside. A young 

 broad sp. measures long, '77, long. spir. '3, lot. '52, div. 70. 



An elevated sp. T24, '64, 7, 50. 



The largest sp. 1'37, '64, '85, 60. 

 Rob West Coast America, between 12*3 and 21 '5 K Lat : 



viz, G-ulf of Papagayo, 8-14 fm. ; San Bias, 7 fm. Hinds. 



Mazatlan ; very rare ; L'pool Col. 



Tablet 1813 contains 4 sp. exhibiting extremes of variation. 



J,, 446. CANCELLARIA GONIOSTOMA, Sow. 



Proc. Zool. Soc. 1832, p. 51 : Conch. III. no 47, pi. 13, f. 43 : 



Thes. Conch, p. 427, no. 64, pi. 94, f. 4Q.Mull. Syn. Nov. 



Test. Viv. p. 73. Mice, in Zeit.f. Mai. 1850; p. 181, no. 53. 



C. B. Ad. Pan. Shells, p. 134, no. 157. 

 Comp. Cancellaria costata, Gray, Soiv. Thes. Conch, sp. 60, 



p. 456, pi. 95, f. 60, 61 ; pi. 96, f. 103 : + C. rigida, Sow. 



(Gambia.) 

 Comp. C. brevis, Sow. Conch. III. f. 33 : Kien. Icon. Conch. 



p. 14, no. 9, pi. 7. f. 2. (Patagonia, Kiener.) 



