TKSTACULLA MAU(JEI. 



Description. — Animal ulonnate, iilUniuiil,B anluiidily ami vory tumid towards 

 tlio vuar; (JO-IOII mill, in k'lij^tli wlioii fully cxloiidcd, but vuiy sliort and cylindrical 

 M-lien contracted ; ilHol'N'l) r(iLOUi; i;royisii-\vliito to black, but n.'^nally of an eartliy- 

 biow n, |ialor laterally and iK'siiriiiklcil witli dci'ii-brown spccUs, wbicli are most 

 plcntif\il on llie back; tlic lonjjitndinal dorsal furrows are well dellncd and enclcjse 

 a double row of consi)icuous tubcicles ; LAM'KKAL KUlutows dee|ily incised and mncli 

 wider apart at tbeir orij^in at (bo iieriiiallial furi'ow tban in llie allied sjiecies; 

 JiANTLh: .sparingly maculate, and sometimes partially onveloiiinK tlie sliell ; .soi.n 

 similarly but more briglitly colored tban tlie body, wbitisb, yellow, pink, or even 

 black, KOdT-FRiNdE sometimes marked with perpendicular lineoles, as in Ariuii ; 

 sLiaiK ('olorlesfi and mil very tenacious. 



Shell subijuadrately oblonj;. very cimve.v, compressed or sligbtly sinuate at front 

 margin, and about one-sixtb of tlie total lenj^tb of tlie animal M'ben extended, wliitisli 

 wilb a brown jieriostracum wliicli becomes abraded from all tlie more e.vposed parts 

 of tlie sliell ; .SPlliK prodnced and terminal, consistinj;' of about IJ wdiorls; LINES OF 

 (M:0WTlt variable but often stronj;' and irrej>'ular ; AI'EUTUKE oblong, very large, 

 outer margins sligbtly expanded, interior slightly nacreous; t'ciLUMELLA narrow, 

 convex, and regularly arclied. Length, lo mill..; breadth, 7 mill. ; alt., 4 mill. 



InTEENALLV, the liEl'LODUCTnE SYSTEM is simple 

 in its organs and their arrangement, and characterized 

 by a short PENIS-SHEATII, very narrow below, but 

 abruptly swollen abo\e. without a KLAGEliU'li, bnl 

 with a strong terminal EETUAC'Tdli, which is attached 

 dorsally to the outer iiitegiiment towards the rear of 

 the body ; the V.MIIN'.V is much shorter than in T. sriilii- 

 liiiii, and consideralily less dilated above ; (AOTESTIS 

 greyisli (ir yellowish-white, composed of loose oblong 

 follicles inil_iedded within the digestive gland and ditli- 

 cult to isolate; llEUMAPllliODlTE liuOT very tortuous 

 and enlering the albumen gland very high up; ALnu- 

 IMEN GLAND enormous, linguiform, of a yellowish or 

 ochreous tint; OVIDUCT clear bluish-white, with broad 

 ample fcdds ; s|'ki;m-iiuct opaque, bull' or cream- 

 cohiurcil; v.\s DEKEliKNs stillly convoluted at its origin 

 from sperm-duct, and entering the penis sheath at the 

 free end, close to the retractor muscle ; si'ERM.\'i'ilE(.'.\ 

 globular or roundly-oval, clear grey, marked supcrlici- 

 ally with wdiite vein-like markings, and imbedded in 

 the base of the albumen gbind, to which it has muscular 

 attachment; sI'KI:m.\'I'I1E('A duct long, about three 

 times the diaiiieler of \esicle, thickened at base and 

 longitudinally strijied, the upper half adherent to oviduct, the lower half sometimes 

 attached to vagina by a stout muscle ; AritlUM short. 



The ALi:\iENTARY CANAL willi short (E.soi'iiAiiUs, opening out into a broadly 

 oval or iiyriforni CliOl', which is whitish wdien empty, and has thick walls especially 

 towards the pyloric end, with the whole surface corrugated with longitudinal anil 

 transverse wrinkles, and attached to left side of liody by a sheet of muscles ; the 

 ^■c■stigial STOM.VCII, a small, while, rounded iirotuberance, is at lirst bend of gut, 

 at the iioint where the intestine enters the digestive gland and receives the thick 

 white bile ducts; the DRiES'l'lVB CLAND is brownish bull', speckled or reticulated 

 with white; ini'Ks'jtne \'ery stcuit in its early course. 



The TENT.VCULAR RETRACTORS of T. iiimii/fl are especially remarkable for their 

 curious asymmetry and ine(|uality ; the left retractor is allixiid to the body-wall of 

 the left sitle, close to the margin of the 

 foot sole, while the noticeably longer right 

 tentacular ninside is attached to the scde also 

 (juite to the left of the median line of the body. 



The LiN(inAL siiEA'i'ii presents the same 

 ]iearly-wliite glistening appearance which 

 characleiizes that of tlie preceding species, but 

 it is coiiiiiarati\ely smaller and its retractors 

 more siiii]ile, consisting of two to live |iairs of 

 ]iartially-iiidrpendent and ]iowerful terminal muscdos, any one of which exceeds in 

 mass (he cephalic retractor of Ariuii- ain- or Liiiiitx iiiii.fiiiiii.s, all with common point 

 of llxation to the integument on the left side of the body beneath the shell. The 

 laleral mu.sclos so consiiicuous in T. ImlinliiliK and T. snihilidii are quite absent. 



KiG. \\'l. — Sexual organ;, of 

 'rcsiacctla man^ei Xl^. 



(Biislol, Mr. J.W. Cundall). 



alb.g. albumen gland ; ot. ovo- 

 tcstis ; (77'. oviduct ; p.s. penis 

 sheath ; r.ni. retractor muscle ; 

 sp, .spermatheca ; sf>.d. sperin 

 duct ; r'.*/. ^■as deferens. 



Ell.. 33.— Linj5ual sheath of Tijstacclla 

 iiiaiii;Li\ illustrating the retractor muscles of 

 the tentacles and lingual sheath. 



