500 MVRICIDM. 



M. SMITHII, Forbes. 

 Mangelia striolata, Brit. Moll. iii. p. 483, pi. 114 A. f. 1, 2. 



Animal spiral, inhabiting a yellowish-brown plicated shell 

 of nine volutions ; ground colour white throughout, thickly 

 mixed with opake intense snow-white flakes, and on the 

 siphon with eight or nine bright pink spots. The mantle 

 is rather tumid at the margin of the aperture, and is pro- 

 duced into a short, fleshy, rather open or scoop-shaped bran- 

 chial fold, which, on the march, is carried somewhat beyond 

 the termination of the canal ; it also lines the anal sinus at 

 the upper angle of the outer lip, which some authors term a 

 pleurotomic scission. The head is the usual flat muricidal 

 one, having at its centre the vertical fissure from which the 

 ordinary armed proboscis is emitted. The tentacula are short, 

 and the portions as far as the offsets, on which the large black 

 eyes are fixed externally, are thick and strong, but the conti- 

 nuations are exceedingly short fine filaments. 



I consider the present, of all the species I have examined, 

 as that which has the eyes nearest the points. The foot is 

 exactly truncate in front, and scarcely eared at the external 

 angles ; in repose it is puckered and rounded posteally, but 

 on the march it extends to a tolerably lanceolate termination. 

 There is no longitudinal line on the sole, nor trace of an oper- 

 culum ; it is bevelled laterally from the long pedicled base by 

 which it is fixed to the body, and also slopes 'from the anteal 

 truncation to a sharp edge. 



The animal is rare at Exmouth, and inhabits the coralline 

 zone ; it is extremely free, and gives every facility for exami- 

 nation; it scarcely differs from M. attenuatus, or the type, 

 M. gracilis. 



It appears that the Murices of this section, none of which 

 much exceed an inch in length, are all without opercula, and 

 have erroneously been considered the Pleurotomata of La- 

 marck, who constituted the genus Clavatula for some of the 

 species, but afterwards abandoned it. The true Pleurotomata 

 have all a deep sinus or emargination in the upper angle of 

 the outer lip of the shell, and a corresponding scission in the 



