61 



Fodskiven er bred, næsten skiveforrnigt udvidet med 

 en ty ml. uregelmæssig Rand og en temmelig jævn Under- 

 flade, beklædt med en tynd, chitinagtig Membran, der 

 fæster den til den Gjenstand, hvorpaa den sidder, hvilken 

 i Almindelighed er døde Skaller af Astarte; kun et 

 Exemplar syntes at være løsrevet fra den almindelige 

 Befæstningsgjenstand , og hos det. var Fodskivens Rand 

 indbøiet over en Lerklump, tier i dette Tilfælde dannede 

 Befæstningsgjenstanden, Tab. IV. Fig. 9. 



Saavel Fodskivens Overflade som de nederste to 

 Trediedele at' Kolumnen ere beklædte med en grovt inkru- 

 steret, membranøs Skede, der foroven har en rund. jævn, 

 men stærkt udpræget Rand, Tab. IV, Fig. 9 a; Tab. XIII, 

 Fig. 5 a. Denne inkrusterede Del af Kroppen aftager 

 successivt i Tykkelse, saa at den øverste Rand er knapt 

 halvt saa bred som det nederste Parti ved Fodskiven, Tab. 

 IV. Fig. 9. Den øverste Trediedel er cylindrisk, nøgen, 

 glat, lidt smalere end Skedens Rand og forsynet med 

 Længdefolder. imellem hvilke tindes fine Furer, Tab. IV, 

 Fig. 9 b; Tab. XIII, Fig. 5 b. Paa Folderne iagttages 

 dels smaa runde Vorter med en Grube i Midten (Suckers), 

 dels Cinclides. De første have en Tendents til at danne 

 Tverrækker, der dog ere meget uregelmæssige ; de sidste 

 ere aflange Spalter, der kun ere sparsomme, og igjennem 

 enkelte af dem stikker en Acontie frem. 



Mundskiven er næsten plan. Munden er aflang med 

 tykke Læber, der danne 5 Folder paa hver Side af Mund- 

 vigene (Gonidialgruberne), Tab. XIII. Fig. 5. Tentaklerne 

 staa i 2 Rækker, 12 i hver; de ere retraktile, ikke meget 

 lange, omtrent som Skivens Bredde. 1 den yderste Række 

 sidde Tentaklerne lige i Kropsranden og synes at være 

 lidt tykkere end de i den inderste Række, der sidde af- 

 vexlende med de første, Tab. XIII, Fig. 5. Hele den 

 nøgne, øverste Del af Kroppen med Mundskive og Ten- 

 takler kunne med Lethed trækkes ind i den inkrusterede 

 Skede og derved ganske skjules af denne, der da antager 

 snart Formen af en afstumpet Kegle, snart af en fladtrykt 

 Halvkugle, Tab. XIII, Fig. 6. Borttager man den inkru- 

 sterede Skede. saa frembyder Kroppens Overflade et yderst 

 rintkornet Udseende, der under Loupen viser sig at være 

 tætstaaende, smaa Vorter, fuldkommen lig dem paa den 

 nøgne Del, Tab. XIII, Fis:. 6 a. 



Farven. Den inkrusterede Skede. der bestaar væsent- 

 ligst af grove Sandkorn, er graabrun ; den nøgne Del af 

 Kroppen er næsten livid. Tentaklerne i yderste Række 

 ere violetrøde, intensere ved Grunden; de i den inderste 

 Række ere mere rosenrøde. Mundskiven er violetrød, 

 straalet med violette Striber. De foldede Mundlæber ere 

 intensere violetrøde. Kropshuden indenfor Skeden er 

 ganske hvid. Vorterne skinne lidt i det Gule. 



The pedal disc is broad, almost discoidally expanded, 

 has a t li in irregular margin and a råtner even under-sur- 

 face clad with a thin, ehitinous membrane that secures it 

 to the object upon which it is seated, usually shells of 

 dead Astarte; only one specimen appears to be torn 

 from the usual object of adhesion and, in it, the margin 

 ut' the pedal disc was curved over a lump of clay, which 

 in this case formed the object of adhesion (Pl. IV, fig. 9). 



Bøth the upper-surface of the pedal disc as well 

 as the lowest two-third parts of the coluinn are elad with 

 i coarse encrusted membranous sheath, which at the top 

 has a round, even, but strongly prominent margin (Pl. IV, 

 fig. 9 a ; Pl. XIII, fig. 5 a). This encrusted part of the 

 body diminishes, gradually, in thickness, so that the upper- 

 most margin is scarcely half the breadth of the lowest part 

 at the pedal disc (Pl. IV, fig. 9). The uppermost third 

 part is cylindric, bare, smooth, slightly narrower than the 

 margin of the sheath, and is furnished with longitudinal 

 folds between which fine furrows are observed (Pl. IV, 

 fig. 9 b; Pl. XIII, fig. 5 V). On the folds there may be 

 observed, partly small round nodules with a cavity in the 

 middle (suckers), partly cinclides. The first-named have a 

 tendency to form transversal series, which are, however, 

 very irregular; the last-named are oblong fissures which 

 are only sparingly present, and through some of them an 

 acontia is protruded. 



The oral disc is almost plane. The moutli is oblong, 

 with thick labiæ which form 5 folds on each side of the 

 oral angles (gonidial groovesj (Pl. XIII, fig. 5). The 

 tentacles are placed in 2 series. 12 in each; they are 

 retractile, not very long, about the breadth of the disc. 

 In the outermost series the tentacles are seated quite at 

 the margin of the body, and appear to be a little thicker 

 than those of the innermost series, which are placed 

 so as to alternate with those of the first series (Pl. 

 XIII. rig. 5). The entire, bare, uppermost part of the 

 body with the oral disc and tenta,cles, can be with- 

 drawn with case into the encrusted sheath. and is 

 thus quite concealed by it. and the sheath then assumes, 

 sometimes the form of a shortened blunted cone, some- 

 times of a flattened hemisphere (Pl. XIII, fig. (3). AVhen 

 the encrusted sheath is removed, the external surface 

 of the body then presents an extremely fine granulated 

 appearance, which, under the magnifier, shows itself to 

 arise from compactly placed, small nodules, quite similar 

 to those on the bare part (Pl. XIII, fig. 6 a). 



Tlie colour. The encrusted sheath, which consists 

 principally of coarse grains of sand, is grey-brown ; the 

 bare part of the body is almost white. The tentacles of 

 the outermost series are violet-red with a more intense 

 colour at the base; those of the innermost series are more 

 rosy-red. The oral disc is violet-red radiated with violet 

 stripes. The folded oral labiæ are a more intense violet- 

 red. The integument of the body, inside the sheath, is 

 quite white. The nodules (suckers) a lustrous yellowish- 

 colour. 



