240 MAZATLAN UNIVALVES 
298. VITRINELLA MONILE, 2. S. 
V. t. subelevata, helicoided, diaphand, alba ; anfr. iv. et 
dimidio, convexis, quarum tres primi leves sew spiraliter sub- 
striati sunt, subito in superficiem minutissime decussatam mutan- 
tes; liris quoad xx. spiralibus, transversim decussatis, interstitiis 
subovalibus seu subquadratis; apertura spatiosa, peritremati 
continuo, parum ab anfr. penult. timpresso, labro ut in Lanthind 
sinuato ; umbilico anfractus intus vix monstrante, regione wm- 
bilicals valde incurvata. 
This species is intermediate in form between V. decussata 
and V.monilifera. The decussating structure, which covers 
the surface and enters the umbilicus, is extremely fine; the 
suboval punctures (in a favourable light) appearing hke rows 
of pearl necklaces. The adult portion rarely extends to a whirl 
and a half. Nearly 30 specimens were found, more or less 
perfect ; of which the smallest is ‘023 across; the largest 
measures Jong. ‘035, lat. °055, by °045, div. about 125°. 
Hah.—Mazatlan ; very rare, off Cham and Spondyli: L’pool 
Col. 
Tablet 1149 contains 1 imperfect, and 3 perfect specimens of 
different ages. !n one, the spiral lines suddenly become more 
numerous. 
299. VITRINELLA MONILIFERA, 7%. s. 
Vit. “V. monili” sculpturd et indole simili, sed discoided, 
anfractibus subplanatis, decussatione tenuiore, umbilico maximo, 
anfractus ad apicem monstrante ; apertura vix continua, sin- 
wath. 
This species might without impropriety be ranked with 
Cyclostrema; the apical portion however is as in Vitrinella. 
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.monile. Long. °015, lat. ‘04 by *035. 
Div. about 175°. 
Hab—Mazatlan ; 7 specimens in Chama and Spondylus ; 
LI’pool Col. 
Tablet 1150 contains the largest and the most characteristic 
specimen. 
