OF MOLLUSCA. 163 



Tongue of Scutus linear elongate, broad, brown. Teeth 

 00 * 5 * 1 * 5 * 00 ; central very broad, transverse ; inner lateral linear, 

 narrow ; upper part narrow, recurved ; central lateral strong, large ; 



Fig. 88. — Teeth of Scutus australis. 



apex hooked, transparent ; external lateral numerous, linear, with a 

 small, transparent, apical hook (fig. 88). 



2. TUGALIA. 



Shell oblong, narrowed in front ; back elevated, cancellated ; apex 

 posterior and recurved; aperture crenulated on the edge, deeply 

 sinuated in front. 



1. T. elegans. 



b. Vent anterior. Shell exposed or partly covered with the mantle, 

 with a slit in the front margin. 



3. Emarginula. 



* Mantle enclosed. 



). E. fissura, Milller, t. 70. f. 4, 9, t. 113. f. 5. 

 Far. rosea, Forbes, B. M. t. B.B. f. 1, 2, 3. 



2. E. elongata, t. 110. f. 3. 



3. E. crassa, Forbes fy Hanley, B. M. t. C.C. f. 1. 



** Mantle much expanded, partly covering the shell. 



4. E. Cuvieri, t. 114. f. 8. 



The young of Emarginula fissura have a very minute, recurved, 

 spiral shell, with rapidly enlarging and finely striated whorls without 

 any slit. — Loven. 



Central tooth of Emarginula crassa laminaceous, flat, obliquely 

 subquadrate, wider at the base, the cutting edge smooth ; four lateral 

 imbricated, laminaceous, oblong, first and second truncated above, 

 third and fourth apiculate, and furnished outside with a longitudinal 

 bent crest. Lateral series of teeth about sixty ; first by far the 

 largest and thickest, the hook lobe-bearing behind ; scape within 

 with a prominent tubercle, base within sharply produced, furnished 



m 2 



