LITUOLA. 



[ 473 ] 



LIVER. 



composed of cartilaginous filiform im- 

 braiK-hfd filaments, at iirrt solid, al'teiwards 

 tubular, composed of several rows of cells ; 

 epijiliYtic on Chorda filmn {L. ptmllus) and 

 Alaria [L. Laiuinaricc), the former 2 to (>" 

 long, the latter 1-4 to 1-2". The spuranges 

 occur either solitary or aggregated, scattered 

 on the surface of the filaments, which in 

 L. pusillus are clothed with pellucid hairs, 

 in L. Laniinarice smooth. 



BiBL. Ilarv. Mar. AUj. p. 43, pi. 8 1) ; 

 Thuret. Ann. Sc. Nat. 4 ser. iii. p. 14. 



LITU'OLA, Lamarck. — A protean Fora- 

 miniferal genus, abundaut both recent and 

 fossil; characterized by the test being coarsely 

 arenaceous, with Httle or no calcareous 

 cement. The shell may be unilocidar (Pro- 

 teonina?, Williamson). If compound, its 

 shape may be loosely moniliform (^Reoplucr, 

 Montfort), whether straight, coiled, or 

 irregular, fi-ee or attached (the latter 

 feature chai'acterizing Placopsilina, D'Orb.). 

 Or the chambers may be close-set and 

 OAerlapping, and have either a straight, 

 coiled, or crozier-like contour, imitating 

 various forms of other Foraminifei'a, such 

 as Ortkocerina, Nudosaria ,Flabe.Uina, Crist el- 

 laria, SpiroUna, Pofalia, Nonionina, Glohi- 

 gei'ina, Orbidina, &c, Further, the chambers 

 may communicate by a simple central 

 aperture, or by a cribriform septal plate ; 

 and they may be either simply hollow, or 

 labyrinthic from secondary gxowths. Some 

 with a single aperture and imdivided 

 chambers, and some which are labyrinthic 

 and cribriform, belong to Reuss's Ilaplo- 

 phragmimn and Haplostiche (straight). 

 When the aperture is of a horse-shoe shape 

 and subvalvate, we have the allied Hlppo- 

 orpina, Parker. PI. 23. tig. 18 is an irre- 

 gularly nautiloid, labyrinthic form (Litiiola 

 difformis) very common in the Chalk. 



Bill. Carpenter, Introd. p. 143. 



LITUO'LIDA, Carp. = Lituolid^ and 

 AsTROEHiziD.^, p. 332. — Besides the 

 coarse-grained genus Lituola (with its sub- 

 divisions), there are several closely related 

 forms which differ chiefly in the degrees of 

 smoothness and compactness with w^hich 

 the constituent sand-gi'ains, and sometimes 

 spicula, are set and cemented. 



Botellina, Carpenter, is a long, roughly 

 segmented tube of sand and spicules, with 

 ill-defined terminal aperture. Saccammhia, 

 Sars, is spherical and smooth, either single 

 or in twos or threes united by a narrow 

 stolon-tube. This is found fossil in the 

 Lower Carboniferous strata, as well as 



recent. Pilulma, Carpenter, quite spherical, 

 with a fissure-like mouth, is composed of 

 very fine sand and points of spicules. As- 

 frorhiza, Sandahl, relatively large, has a 

 coarse, iri-egularly stellate, test of loosely 

 aggregated sand, with pseudopodial aper- 

 tures among the granules, chiefiy at the 

 ends of the digitate radii, llhadammina, 

 Sars, arenaceous, with a cement containing 

 ferric phosphate, is tubular, forked, or 

 radiate, usually trifid, with a central cavity; 

 openings at the radial ends. 



The Lituolida with fine-grained and smooth 

 tests are best typified by Trochanimina and 

 its subgenus lVehhi)ni (D'Orb., restricted). 

 These range from simple, attached, tent-like, 

 single or multiple tests ( W. hemispharica, 

 W. irref/idaris, &c ),to the tubular and spiral 

 Troch.incerta(F\. 23. fig. 14) and therotalioid 

 T. s<p(amata et injlata. The rotalioid and 

 fusuline Endothryce and the nummulitoid 

 Involufina, all fossil, belong to the same 

 category. 



Valvulina, one of the Textulamid^e, 

 sometimes finely, sometimes coarsely arena- 

 ceous, is, in this character, allied to the 

 Lituolines and Trochamnrines ; and among 

 its several modifications some link it with 

 LHuola and others with Trochammina. 

 Tetraf axis has an alternation oi four, and 

 Valvulina (PL 23. fig. 20) of ^7j?ee chambers. 



The Lituolida are represented in every 

 existing sea, and in every geological forma- 

 tion as far back as the Carboniferous. 



BiBL. Carp. Introd. 140 ; Bescr. Cat. 3Iic. 

 Soc. April 1870, 4 ; Parker, Jones, and 

 Brady, Phil. Tr. civ. 406; Monogr. Crag 

 For.^Pal. Soc. 25 ; Brady, Mon. Carl. For., 

 Pal. Soc. 1876 ; Qu. Mic. Jn. n. s. xxi. 



LIVER. — The glandular organ which 

 secretes the bile. 



On examining the surface or a transverse 

 section of the liver with the naked eye, it 

 usually presents a mottled appearance, 

 numerous spots of a dark or light red 

 colour being surrounded by a margin of a 

 paler or darker colour. These spots cor- 

 respond to the lobules of the liver. 



The lobules are rounded or polygonal, and 

 about 1-2 to 1'" in diameter (fig. 405). 



Between the lobules run branches of the 

 vena portae, forming the interlobular veins 

 (coloured red in PI. 39. fig. 33) ; these 

 throughout their course send off numerous 

 smaller branches into the substance of the 

 lobules, which terminate in the capillary 

 plexus of the lobules. 



The branches of the vena poilaj are accom- 



