KXTOMOSTOMATA. 



ENTOMOSTOMATA. 



The Una Entomology literally signifies discourse upon insect*, it 

 being derived from the two Greek wordi "trrafur, an insect, and Aiyot , 

 a discourse. 



The term Entoma was first applied to these animal* by Aristotle, 

 and U synonymous with the Latin word itureta (whence ii derived the 

 English nme 'insects'), l>oth hnvinc n-frrrnce to a striking character 

 exhibited in the insect tribe, that of having the body infected, or, aa 

 it were, out and divided into numerous segments. [I.VSECTA.] 



KNTOMOSTO'StATA, De Blainville's name for his second family 

 of his first order, Sip*<mobrackiata, of his fimt sub-class ParacepMa- 

 bpAora ZMoKO, of his second class, ParacephaloiAora, of Malacixoa. 

 This family appears to be nearly the same with the genus fiuccinwn 

 of Linnipus and family liuecjiiitlir of other naturalists. It is thus 

 characterised by De Blainville : 



Animal spiral, with the foot, which is shorter than the shell, 

 rounded in front Mantle provided in front of the respiratory cavity 

 with a long canal always uncovered, which the animal uses as an 

 organ of prehension. Head furnished with a single pair of blackish 

 tentacula, which carry the eyes on nn enlargement (renflement) of the 

 half of their base. Mouth armed with a proboscis, as in the preceding 

 family (Siphonottomata), without any labial tooth, but with a small 

 tongue. Organs of respiration formed by two unequal pectinated 

 branchiae Organs of generation termination of the oviduct in the 

 females at the right side, at the entrance of the branchial cavity. 

 Termination of the deferent canal at the extremity of a long flattened 

 contractile excitatory appendage, situated at the right side of the 

 neck. Shell very variable in form, whose opening, sometimes very 

 Urge and sometimes very small, is without an apparent canal, or with 

 a Tory short one suddenly recurved upwards, but always more or less 

 deeply notched anteriorly. Operculum horny, unguiform, oval, sub- 

 concentric, with the summit a little marked and marginal. 



De Blainville observes that this family differs evidently very little 

 from that of the Si/tkonoitomata, whether in the soft parts or in the 

 ahelL The species which it embraces are not all absolutely marine, 

 though a very great number of them are : some live at the mouths of 

 rivers, and a very small number are entirely fluviatile. 



The following are the principal genera of this family : 



* Tnrriculated. 



Crrithium. Animal very much elongated, the mantle prolonged 

 into a canal at its right side, but without a distinct tube ; the foot 

 terminated by a depressed proboscidiform muzzle ; tentacula very 

 distant, with large rings, swollen, as it were, in the lower part of 

 their length, and carrying the eyes at the summit of this enlargement. 

 Mouth terminal, in the form of a vertical slit, without any labial 

 tooth, and with a very small tongue furnished with regularly disposed 

 reflexed teeth. A single straight bronchia. 



Animal of CrrilHum Ttlaeopivm, and shell of Crrithium paluttre. 



Shell more or len turriculated, tuberculous ; aperture small, oral, 

 oblique ; the columcllar border very much excavated, callous ; the 

 right lip sharp-edged, and dilating a little with age. Operculum 

 horny, oval, rounded, sub-spiral, and striated on iU external surface; 

 sunk, and bordered on its internal surface. 



a. 

 Species which hare evidently a small canal, very short, and obliquely 



recurved towards the back. 

 Ex. C. Veriagvt. Locality, Indian Ocean and Moluccas. (Lamarck.) 



& 



Species which have a still smaller canal, but straight throughout, 

 and a well-formed sinus at the posterior union of the two borders. 

 Ex. C. Aluto. Locality, Indian Ocean and Moluccas. (Lam.) 



fy 



Species whose aperture is divided into three by the shutting of the 

 short anterior tube, and that of the posterior sinus. (Genus, 

 Tnpkor,, or Trutome (Deahayes), Trifont(\), Deahayea. 



Ex. U. irutvma. 



Species which have a small straight canal, and the whorls of the 

 spire flat and ribanded, with a deep umbilicus, two decurrent 

 plaits on the columella, and one on the right lip. (Genus, 

 fferinea, Defranco.) 



Ex. C. Nerinta. 



t. 



Species which liave DO canal, but a simple notch, and whose right 

 lip is much dilated in age. (Oenus, Potamida, Brongniart; 

 Pyrasut, De Montfort.) 



Ex. C. palutlrt. Locality, coasts of the East Indies, in the salt 

 marshes. (Lam.) 



C 



Species whose aperture, without a canal, is a little notched in front 

 aud rear, the notch being replaced by a sinus ; the columellar 

 border curved in its middle ; the right lip not dilated. (Genus, 

 f'irrna, Lam.) 



Ex. C. ifadayatcarieiisc. 



a, Crrithium Uadagatearimtt (Lam.) ; b, C. Madngatearienir (Pirena, Lam.', 

 according to DC Blainville. N.B. It i not clear that these are not the name 

 ipecict, notwithstanding the comparative smoothncu of 6. 



De Blainville makes the genus Cerithium, as established by him, 

 contain 66 species characterised by Lamarck ; adding that the greater 

 part are marine, but many from the mouths of rivers, and some 

 entirely lacustrine, and that there is but one belonging to the French 

 seas, whilst more than a hundred fossil species ore found in France 

 and Italy. M. Defronce's genus fferinea, he remarks, would be 

 better placed among the PyramideUa. 



The species of this genus with those of Potamida, fferinea, Aporr- 

 Kent, and Struthiolaria, are often referred to the family Certhiada, 

 (Woodward, ' Manual of the Molluscs,') 



Lamarck places Cerithium at the commencement of the first section 

 (Canaliferes) of his Zoophagous Trachelipods, immediately after Turri- 

 tella, the last of his Phytophagous (Plant-Eating) Trachelipods. 



r gives it a position after Purpura, Ctura, and Trrtbra, and 

 before Murex. This, as the Rev. M. J. Berkeley and Mr. Hoffman 

 observe, in their interesting paper on the anatomical structure of 

 a m Tdetropium, would imply a structure of the parts of the 

 mouth adapted for boring shells, according to the known habits of 

 Murr.r and certain allied genera ; but, they remark, a single glance at 

 Adanson's figure is sufficient for conviction that the animal is much 

 more nearly allied to the Trochoidet ; and that Lamarck judged 

 rightly, according to the evidence before him, in placing it on the 

 confines of his two great classes. This is corroborated, they add, by 

 the little additional information of M. Sander Rang, who describes 

 the month as toothless, but furnished with a small tongue. 



M. Sander Hang states that this genus, so numerous in species both 

 living and fossil, contains only marine animals ; but, nevertheless, 

 there are some of them which live at the mouths of rivers, and these 

 are precisely the individuals which M. Brongniart has united to form 

 the genus Potamida, which cannot be adopted in Zoology, inasmuch 

 as it does not rest upon sufficiently marked characters. M. Rang 

 adopts generally the divisions of De Blainville with approbation, but 

 he rejects the sixth group (0, which comprehends the genus Pirrna, 

 which Rang, following the example of M. de Fdrussac, places with 

 Mclanopni. Rang agrees with De Blainville in thinking that the divi- 

 sion containing Dofrance's Nerinea in perhaps doubtful, and that its 

 position would be better near the PyramfdeUer. He observes that 

 they have in France but two or three living C'crithia, but a great 

 number of fossil species. 



Denhayes makes the number of living species eighty-seven; not 

 reckoning Triforu, of which he gives three species, nor Pinna, of 



