Mr. W. Clark on the Muricidse. 113 



Murex septangularis, Montagu et nobis. 



Animal with eight spiral turns, white in all parts, powdered 

 with in tenser minute flake-white points ; mantle rather thick at 

 the edges, and produced into a fleshy branchial fold that extends 

 beyond the short canal of the shell ; the head is compressed, 

 narrow, with a vertical fissure below it, from which a retractile 

 proboscis issues ; the coalition of the tentacula at their bases is 

 not in the least impeded by any projection of the head ; the ten- 

 tacula are short, setose, with the eyes on attached thick offsets 

 at the external points, at about two-thirds of their length ; the 

 remaining portion is very short. Foot rather narrow, slightly 

 auricled, truncate in front, moderately long, with the termination 

 nearly as broad behind as in front, without a trace of a distinct 

 point, though it is often more or less emarginate ; it carries on 

 the upper part a strong, very elongated, oval, pale corneous oper- 

 culum formed of unguiculated segments. The sinus or emargi- 

 nation at the upper part of the aperture is very slight. 



This species is not often obtained alive at Exmouth ; its range 

 of habitat is from the littoral to the coralline zone. It has by 

 some authors been deposited in Pleurotoma, on what grounds 

 can scarcely be satisfactorily explained; as the pleurotomic emar- 

 gination is almost obsolete, or less conspicuou.s than in any other 

 of the minor so-called Pleurotomata ; besides, as has been stated, 

 the head is perfectly flat, without a trace of projection to inter- 

 cept the coalition of the tentacula. We consider it in every re- 

 spect a varicose Murex. 



Besides the three species above described, this section com- 

 prises the M. turricula, M. coralUnus, M.Barvicensis, M.Bamffius, 

 M. rufus, M. minimus ?, and perhaps one or two others of the 

 minor Murices. 



Murex et Buccinum, Linnaeus. 



Sectio II. 



Testa inflata, Isevis, effusa, spiraliter striata. Apertura ovaHs. 

 Columella mutica, rariiis subaspera, aut fastigiata. Operculum 

 corneum. 



Murex, nobis. 



Fusus, Lamarck et auctorum. 



The Murices of this section are the Fusi of authors, most of 

 which are deep-sea species, as the M. antiquus, M. Turtoai, M. 

 Norvegicus, M. Berniciensis, M. Islandicus, &c., and the M. tri- 

 chotropis ? None of these, except the M. Islandicus, occur on 

 the southern coasts, and that we have had no opportunity of ex- 

 amining for several years ; but for the type of the animal of the 

 enumerated species, we refer with perfect confidence to either of 



Ann. ^ Mag. N. Hist. Ser. 2. Vol. vii. 8 



