240 MAZATLAN UNIVALVES 



298. VlTEINELLA ilOJflLE, n. S. 



V. t. subelevatd, helicoidea, diaphand, alba ; anfr. iv. et 

 dimidio, convexis, quorum tres primi IcBves seu spiraliter suh- 

 striati sunt, siihito in superficicm mimittssime decussatam mutan- 

 tes ; liris quoad, xs. spiraUbus, transversim decussatis, interstitiis 

 subovalibics seu subquadratis ; aperturd spatiosd, peritremati 

 continuo, parum ab anfr. penult, impresso, lahro ut in lanthind 

 sinuato ; umbilico anfr actus intus vix monstrante, regione um- 

 bilicali valde incurvatd. 



This species is intermediate in fonn between V. decussata 

 and V. monilifera. The decussating structure, which covers 

 the siirface and enters the umbilicus, is extremely fine ; the 

 suboval punctures (in a favourable light) appearing like rows 

 of pearl necklaces. The adult portion rarely extends to a whirl 

 and a half. Nearly 30 specimens wei'e found, more or less 

 perfect ; of which the smallest is '023 across ; the largest 

 measures long. "035, lat. "055, by '015, div. about 125". 



Hab. — Mazatlan ; very rare, oflf Chamae and Spondyli : I! pool 

 Col. 



Tablet 1149 contains 1 imperfect, and 3 perfect specimens of 

 different ages. In one, the spiral lines suddenly become more 

 numerous. 



299. VlTEINELLA MONILIFEEA, n. S. 



Y.t. "V. monili" seulpturd et indole simili, sed discoided, 

 anfractlbus subplanatis, decussatione tenuiore, umbilico maocimo, 

 anfractus ad apicem monstrante : aperturd vix continud, sin- 

 uatd. 



This species might without impropriety be ranked with 

 C3'clostrema ; the apical portion however is as in VitrincUa. 

 The mouth is scarcely altered in form by the penultimate 

 whirl, and is sinuated as in Adeorbis. The necklace pattern is 

 rather finer than in V. monde. Long. *015, lat. '04 by '035. 

 Div. about 175". 



Hab. — Mazatlan ; 7 specimens in Chama and Spondylus ; 

 Upool Col. 



Tablet 1150 contains the largest and the most characteristic 

 specimen. 



