1:1 MINUS, i ;', 



posed entirely of -pines, extend- from the mouth ilnwn to a tnuwverae 

 elliptical arrangement, tin- shelly portion, constituting the ellip.-e. ' 

 |uite Miiiintli. Tin- ti.iiisveree arrangement sometimes resembles a deep 

 deft in the .-hell. Kilt here then- is none. 



Much diH'erence in the perfection and numl>er of the pore*, and of the 

 \:irioui superficial figures and nppcarance, distinguishes diflerent flu-Ik 



The Mibtrtance of all is very hrittle, thin, and liirht, compjuxnl with 

 their dimensions. 



This animal is usually sunk amidst the sand, of which it swallows an 

 extraordinary quantity, so that its weight becomes surpri*<im{ and un- 

 natural. Comminuted shells, of various species, are mixed with the sand, 

 luit their inmates do not appear to have been rendered prey. No hpr, i 

 men has i'e<l on any substance offered to it in captivity. 



Professor h-ll,' ( I,, ,11, gives dissections of this Mil.j. 



1'IVTEXXXII 



Fir.. 12. Spatanpu purport**, reduoed, under nurfaoe. 

 13, 14. Suckers enlarged. 

 r Shell divested of tho tpine, nhewing the AtollaU- fimin- <>n tin 



convex or upper mde. 



16. Shell divested of tho Rpinee, hewing the site and fiMurc <>f tin- 

 Mi' Hi th, under surface. 



3. SFATAXGUS (FLAVESCENS), XIVEUS. Plate XXXIII. figs. 1, 2, :i, 4. 



5, 6, 7, 8, 9. 



This is a fine and delicate looking animal, somewhat lieart-*ha|Mil 

 like the preceding, hut thicker in proportion, and the partw more pro- 

 minent or rounded. 



The largest specimens falling into my possession, extended t\\<> 

 1 1 H -lies and a half in length. Others were about an inch and a half, 

 nearly two inches broad, and one in thickness. Such dimen-iniui are to 

 be understood as of animals invested with the white or yellow spine*, 

 wherewith they are totally coven-d. 



