I 



MAZATLAN TTNIVAIVES 421 



Tablet 1972 contains 9 sp. very young.— 1973, 8 do. adoles- 

 cent.— 1974, 9 do. adult, various sizes.— 1975, 3 do. repaired 

 after fracture.— 1976, 2 sp. with opercula.— 1977, 1 sp. beauti- 

 fully encrusted, auotber with broken lip shewing the fold 

 within, and 2 dead sp. in which state the details of sculpture 

 are conspicuously marked. 



508. Chbysallida telescopium, n. s. 



Chr. t. coded, turritd, alba ; vertice nucleoso, satis promin- 

 ente, anfr. ii. helicoideos verticaliter sitos continence, apiceparttm 

 monstrante, marginihus spircB (testa adolescente) rectis vix 

 superante ; anfr. xii. normalihus, quarumx. planati, in spird, 

 ut in ''Chr. communi," clathris circiter xvi. et lirulis spiralihus 

 iv. decussatis : testa adolescente, lacuna suturali impressd circa 

 basin contimid ; peripherid angulatd, aperturd subquadratd ; 

 testa adultd, basi hand angulatd, effusd, hand lacunatd ; peri- 

 tremati continuo, ad basin late sinuato : basi lirulis spiralihus 

 circiter vii. cinctd, interslitiis vix decussatis ; plied columellari 

 intus acutd, prominente, ad aperturam vix monstrante, declivi. 



This species begins life as a helicoid body, rather large in 

 proportion as in Chemnitzia, which genus it also approaches in 

 the number of whirls. These are flat, with straight margins, 

 having the basal periphery angulated in the adolescent sheD, 

 in which state it approaches the form of Telescopium. The 

 sutural groove, formed by the hollowing oflf of the ribs in the 

 last cancellated division, is then continued round the base. In 

 the last whirl however, the shell is contracted, the base pro- 

 duced, the sutural groove evanescent, the aperture effuse, and 

 a strong continuous labium finally appears. It is known from 

 Chr. communis by the large size of the vertex, taking ofi" the 

 appearance of truncation from the shell ; in the non-adult state 

 by the greater angidation of the base and antesutiiral groove 

 (the ribs in the common species not quite reaching the suture) ; 

 and in all states by the greater divergence, and by the basal 

 striae, which are stronger and less numerous. A specimen in 

 the angular state measures long. '0S2, long.spir. '055, lat. '037, 

 dio. 30°. One almost adult measures long. "125, long. spir. '085. 



Hah. — Mazatlan ; 10 specimens (mostly young) off Chama and 

 Spondj'lus ; L'pool Col. : — do. 3 sp. (one adult) ; Havre Col. 



Tablet 1978 contains the youngest sp., with two and a half 

 normal whirls ; an angular specimen with 5 whh-ls ; a perfect 

 sp. with 6 whirls, normal form, but without the parietal lip ; 

 Dec. 1856. n n. 



