242 



MUSEUM OF ANIMATED NATURE. 



[MURICKS. 



aays il» deiwriber, it must be placed with that genu*, 

 to which it is more nearly related than to any other. 

 A single specimen only was found at Pananoi. 



We now pass to the genus Triton. In this genus 

 the shell is oval with the spire moderate, and the 

 canal rather short ; externally it is in general rugose, 

 with a few varices, scattered and longitudinal in 

 their direction. The aperture is sul>ovai ; the right 

 lip is thickened, the columellar lip covered by a 

 callosity. The operculum is horny, and somewhat 

 oval or muscle-shaped. The raollusk much resem- 

 bles that of Murex*; the foot is thick ; the eyes are 

 placed on an elevation at the base of the taper ten- 

 tacula. The tube is large. The animal of Triton 

 is represented at Fig 2805 ; a. is the operculum. 



The genus Triton is divided into several .sections, 

 as follows : — 



Section 1. The species comparatively smooth, 

 with thickened lines or ridges either very slight or 

 wanting, excepting at the edge of the right lip. 

 Example : Triton variegatus. 



Section 2. The species more tuberculous or 



?>iny, with the aperture more open. Example : 

 riton Lotorium. (Genus Lotorium of De Montloit.) 



Section 3. The species with a shorter spire, al- 

 ways very tuberculous, and most frequently umbili- 

 cated ; a sinus at the posterior juncture of the two 

 lips. Example : Triton cutaceus. (Genus Aquilus 

 ofDe Montfort.) 



Section 4. The species as in section 3, but with 

 the aperture closely narrowed by a callosity and 

 irregular teeth. Example : Triton Anus. The 

 Grimace of collectors. (Genus Persona of De 

 Montfort.) 



The Tritons occur at depths ranging from the 

 surface to thirty fathoms; generally on sandy or 

 muddy bottoms. 



2806. — The Vaeikqated Tbiton 



{Triton variegatus). This handsome species, com- 

 monly called the sea-trumpet, or Triton's shell, is 

 found both in the seas of the West Indies and those 

 of Asia, within the tropics. The shell is elongated, 

 conical, ventricose below, and tiumpet-like in gene- 

 ral contour; it is girt with very obtuse smooth 

 ribs. The ground colour is white, elegantly varie- 

 gated with red and bay ; the aperture is red ; the 

 columellar lip wrinkled with while ; the edge of the 

 outer lip is spotted with black, each black mark 

 having two white dentlculations. 



The genus Triton is abundant in species. Lamarck 

 enumerates fifty-one recent, and three fossil. M. 

 Deshayes gives the number of living species as forty- 

 three, and of fossil species in tertiary deposits twenty- 

 five, of which still six exist in a living state. In 

 the 'Proceeds. Zool. Soc' 1833, p. Set seq., Mr. 

 Broderip describes eight new species, in Mr. Cum- 

 ing's collection, from the west coast of South Ame- 

 rica, and the islands of the South Pacific; and at 

 page 71 Mr. G. B. Sowerby describes eiglit addi- 

 tional new species from the same localities. 



Our next pictorial specimen constitutes an exam- 

 ple of the genus Ranelia. 



The genus Ranelia has the shell oval or oblong, 

 and depressed with two varices situated laterally ; 

 the aperture is oval, the canal short, and a sinus 

 exists at the posterior union of the two lips. It is 

 divided into two sections, one containing the non- 

 umbilicated species, as Ranelia granulata (genus 

 Bufo of De Montfort) ; the other containing the 

 species which are urabilicated, as the Ranelia foliata. 



The Ranellae tenant beds of sand, and rock, and 

 live at depths varying from the surface to ten or 

 twelve fathoms. 



2807. — The Foliated Rakella 



(Ranelia foliata). This species, as we have said, 

 belongs to the urabilicated section. It is a native 

 of the seas of the Mauritius. The characters are 

 thusdetailed by Mr. Broderip: — Shell ovate-conical, 

 \entricose, not compressed, of a flesh or pale rose 

 colour ; with frequent transverse subgranulated low 

 ridges, the interstices between which are longitudi- 

 nally striated ; the whorls are armed with one row 

 of sharp tubercles, the middle ones of which are the 

 longest ; the other ridges of the body whorl are ob- 

 soletely tuberculated here and there; the columel- 

 lar lip is expansive and foliated, and the margin of 

 the outer lip expanded and thin ; the aperture is 

 ovate, very strongly and thickly furrowed, of a rich 

 orange colour, and terminating above in a deep 

 foliated sinus which extends beyond the varix. 



The species of Ranelia are rather numerous ; M. 

 Lamarck describes fifteen in a living stale; M. de 

 Bkinville has described another; and Mr. Bro- 

 derip has added nine, of which eight are from Mr. 

 Cuming's collection: see *Zool. Proceeds.' 1832. 

 M. de Blainville enumerates only one fossil species ; 

 M. de Fiance five, of which three from Italy are 

 identical ; M. Deshayes gives the number of fossil 

 species as eight, of wnich four occur also in a living 

 state. 



We now come to the restricted genus Murex, 

 which may be characterized as follows: — 



Shell oval, more or less eleviited on the spiral side 

 or prolonged forwaids. Its external surface always 

 presents rows of spires, spines, bold processes, or 

 tubercles arranged in regular and constant order ; 

 the aperture is oval, terminated anteriorly by a 

 straight canal, more or less elongated and closed. 

 The right lip is often plaited or wrinkled ; the co- 

 lumellar lip often callous. 



The mollu^k has a short stout foot notched ante- 

 riorly ; the head is furnished with two long approx- 

 imated tentacula bearing the eyes on a thickened 

 portion ; mouth without jaws, but armed wilh hooked 

 denticles in place of a tongue ; mantle large, often 

 fringed on the right side ; operculum horny. Fig. 

 2S08 represents the animal of Murex ; a, the oper- 

 culum. 



The genus Murex is subdivided as follows: — 



Section 1. Species with a very long and spiny 

 tube ; the thorny woodcocks of collectors. Exam- 

 pie : Murex tribulus. 



Section 2. Species with a very long tube, and 

 without spines. Example: Murex Haustellum. 

 Woodcock's head of collectors. (Genus Brontes of 

 De Montfort.) 



Section 3. Species with three elevated, flattened, 

 and comparatively thin varices. Example : Murex 

 acanthopterus. 



Seclion 4. Species with three ramified varices. 

 Example : Murex adustus. (Genus Chicoreus of 

 De Montfort.) 



Section 3. Species which have a greater number 

 of varices, and the tube nearly closed. Example: 

 Murex regius. 



Section 6. Species which are subturriculated. 

 Example: Murex lyratus. 



Seclion 7. Species which are subturriculated, 

 the tube closed ; a tube besides is pierced towards 

 the posterior extremity of the right side, and persis- 

 tent upon the wborls of the spire. Example : Mu- 

 rex pungens ; a fossil. (Genus Typhis of De Mont- 

 fort.) 



Section 8. Species more globular, the spire and 

 the canal shorter; the latter very open : the aper- 

 ture rather wide. 



Section 9. Species which have an oblique fold, 

 very much anterior to the columella, and an umbi- 

 licus. (Genus Phos of De Montfort.) 



The Murices are found in depths ranging from 

 five to twenty-five fathoms, on beds of sand, mud, 

 &c. The species are very mimeruus. 



2809. — TuE CoMMO.N Thoent Woodcock 

 {Murex tribulus). JIurex tenuispina, Lamarck. 



This species, known also by the name of Venus's 

 Comb, is a very beautiful and striking shell, remark- 

 able for the length and slenderness of its pointed 

 spines, arranged in regular order, indicative of the 

 periodical developments of the edge of the mantle. 

 It is found in the Indian Ocean ; specimens are 

 brought from the Moluccas. 



2810. — TiiK Woodcock's Head 



{Murex Hausttllum). In this species the shell is 

 ventricose, naked, destitute of spines, ribbed and ru- 

 gose ; wilh a long slender tube, and a short spire. 

 The colour is fulvous, inclining to red, lineated wilh 

 bay. The mouth is roundish and red. It inhabits 

 the same seas as the preceding. 



2811. — TuE Royal Mukex 



(Murex regius). This splendid shell is found along 

 the western coast of Central and South America. It 

 is one of the ornaments of the cabinet of the con- 

 chologisl ; nor can words convey an adequate idea 

 of its gorgeous colouring. 



In Lamarck's day, sixty-six recent species oi 

 Murex and fifteen fossil species were recorded. M. 

 Deshayes gives the number of recent species, in- 

 cluding those of the genus Typhis (De Montfort), as 

 seventy-five, but this is very far below the mark ; 

 he enumerates eighty-nine fossil species in the ter- 

 tiary deposits. 



Mr. Broderip, in the ' Proceeds. Zool. Soc.,' de- 

 scribes twenty-six new species of Murex Iroin the 

 western coast of South America, and the islands of 

 the South Paciftc, and also five species of Typhis, 

 all in the collection of Mr. Cuming. 



The MuricidiE (Siphonosloniata, De Blainville), 

 and the Buccinidse (Entomosloniala,De Blainville), 

 appear to be the two principal groups of marine 

 gastropods (or trachelipods,* as some prefer to term 

 them) destined to keep down the overabundance of 

 the bivalve mollusks and herbivorous gastropods ; 

 they are the destroyers among the races of their 

 class, and prowl about in quest of prey. They drill 

 the shells which enclose their victim, and drain out 

 its juices, adhering till it is almost utterly con- 

 sumed. Nor is this destruction carried forward on 

 a limited scale. When we consider the number of 



•Tnichelipod,from Tga.'^nXof , the nc?ck ; and w'oy;, iraJaf, a/oot: 

 the foot in tuese moUuak* appearing as if undt'X llic ht^ad and neck. 



species included within the two families in question, 

 and the countless thousands of individuals of each 

 of these species, and reflect ujwn their voracity, we 

 may form some slight idea of the extent ol their 

 operations, and of the consequent influence they 

 must exert in maintaining the balance of crealion. 

 Throughout all seas are these carnivorous mollusks 

 carrying on their appointed work : in ministering 

 to tlieir own necessities, they fulfil the great pait in 

 the vast scheme of creation to which they are ap- 

 pointed. We have now before us a miscellaneous 

 assemblage of shells picked up upon our own shores, 

 and few are undrilled ; some of these carnivora have 

 battened on their tenants, and the waves have 

 washed them on the beach. In other ages, as we 

 have abundant proofs, the plan of destruction, in 

 Older to counterbalance increase among these 

 marine shell-clad molli^sks, was in operation. Dr. 

 Buckland, in his admirable ' Bridgewater Treatise,' 

 gives the following details connected with fossil 

 shells, once the living inhabitants of other seas, 

 when the surface of our planet exhibited a ditt'eieiit 

 arrangement of land and water. 



" Most collectors," says the Professor, " have seen 

 upon the sea-shore numbers of dead .shells, in which 

 small circular holes have been bored by the pre- 

 daceous tribes, for the purpose of feeding upon the 

 bodies of the animals contained within them ; similar 

 holes occur in many fossil shells of the tertiary 

 strata, wherein the shells of carnivorous trachelipods 

 also abound ; but perforations of this kind are ex- 

 tremely r:ue in the fossil shells of any older forma- 

 tion. In the green sand and oolite tliey have been 

 noticed only in those few cases where they are ac- 

 companied by the shells of equally rare carnivorous 

 niuliusks; and in the lias and strata below it* 

 there are neither perforations nor any shells hiiving 

 the notched mouth peculiar to perforating carnivo- 

 rous species. It should seem from these fads that, 

 in the economy of submarine life, the great family 

 of carnivorous trachelipods performed the same 

 necessary ofiice during the tertiary period which is 

 allotted to them in the present ocean. We have 

 further evidence to show that in limes anterior to 

 and during the deposition of the chalk, the same 

 important functions were consigned to other car- 

 nivorous mollusks, viz. the testaceous cephalopods : 

 these are of comparatively rare occurrence in the 

 tertiary strata and in our modern seas ; but through- 

 out the secondary and transition formations, where 

 carnivorous trachelipods are either wholly wanting 

 or extremely scarce, we find abundant remains of 

 carnivorous cephalopods, consisting of the cham- 

 bered shells of nautili and ammonites, and many 

 kindred extinct genera of polythalamous shells of 

 extraordinary beauty. The molluscous inhabitants 

 of all these chambered shells probably possessed the 

 voracious habits of the modern cuttle-fish ; and by 

 feeding like them upon young testacea and Crus- 

 tacea, restricted the excessive increase of animal 

 life at the bottom of the more ancient seas. Their 

 sudden and nearly total disappearance at the cora- 

 meneement of the tertiary era would have caused a 

 blank in the 'police of nature,' allowing the herbi- 

 vorous tribes to increase to an excess that would 

 ulliniately have been destructive of marine vege- 

 tation, as well as of themselves, had they not been 

 replaced by a different order of carnivorous crea- 

 tures destined to perform in another manner the 

 office which Ihe inhabitants of the ammonites and 

 various extinct genera of chambered shells then 

 ceased to discharge. From that time onwards we 

 have evidence of the abundance of carnivorous 

 trachelipods, and we see good reason to adopt the 

 conclusion of Mr. Dillwyn, that in the formation 

 above the chalk the vast and sudden decrease of 

 one predaceous tribe has been provided for by the 

 creation of many new genera and species possessed 

 of similar appetencies, and yet formed for obtaining 

 their prey by habits entirely dift'erent from those of 

 the cephalopods. The design of the Creator seems 

 at all times to have been to fill the waters of the 

 seas and cover the surface of the earth wilh the 

 greatest possible amount of organised beings enjoy- 

 ing life ; and the same expedient of adapting the 

 vegetable kingdom to become the basis of tlie life 

 of animals, and of multiplying largely the amount 

 of animal existence by the addition of carnivora to 

 the herbivora, appears to have, prevailed from the 

 first commencement of organic life to the present 

 hour." (' Bridgewater Treatise.') 



Family STROMBID.E (STROMBUS, PTERO- 

 CERAS, &c.). 



This family constitutes the Angyostomata of De 

 Blainville. In this family are comprehended the 

 shells which, says Cuvier, have the canal straight, 

 or bent to the right, and the outer lip of the aper- 

 ture dilated with age, but always preserving a sinus 

 towards the canal, under which passes the head 

 when the animal extends itself. Most have this 

 sinus at some distance from the canal. 



* Carnivorous g.^tropo-Js occur in llic Silurian rocks. 



