130 



Polyperne hæve sig søileformet fra Coenenchymet, 

 ere cylindriske og lidt indknebne paa Midten, Tab. VI. 

 Fig. 7. 8. Oolumnen er inkrusteret med Sand. omkring 

 20"™ hoi. 6""" bred ved Basis, 6 — l mm bred ved den øverste 

 Ende og 4 ■"•' paa Midten. Naar Polvpen er indtrukken, 

 er den øverste Ende tvers afskaaren med en liden Fordyb- 

 ning i Midten og afrundet Rand. der har 18 Straaler, 

 Tab. VI, Fig. 9. Er Polvpen udstrakt, danne disse Straaler 

 ligesaa mange inkrusterede Ribber, som strække sig et 

 Stykke ned paa Kroppen, og imellem hvilke der er et 

 temmelig bredt, nøgent Felt. Tab. VI. Fig. 7. 8; Tab. 

 XXV. Fig. 5 a,. Mundskiven er næsten flad og foldet. 

 Folderne udgaa fra den lidt aflange Mund mod Peri- 

 pherien. 



Tentaklerne ere temmelig lange, sidde i 3 Rækker; 

 de ere tykke ved Grunden, men ende konisk tilspidsede. 

 Den forst e. y deiste. Rækkehar 18. den anden 12, — kun enkelte 

 Exemplarer 18 — og i begge disse Rækker ere Tentaklerne 

 omtrent lige lange: men den tredie, inderste, Række har 

 kun 6, og disse ere baade de længste og tykkeste. — næsten 

 lige saa lange som Mundskivens Bredde. 



Naar den inkrusterede Sand er delvis afskrabet, sees 

 paa Kroppens Overflade 18 Længdelinier, der staa tæt til 



hverandre og kun adskilte ved en fin, lysere Linie. Farven: 

 Den inkrusterede Kropsdel er gulgrønlig, og naar Dyret 

 er udstrakt. næsten gul, kun ved Grunden spillende nogel 

 i det Gronlige. Mundskiven er svag teglstensrød med 

 mørkere Folder omkring Mumien. Tentaklerne ere intensere 

 røde end Mundskiven. men ere i Enderne noget blegere, 

 Tab. VI. Fig. 7. 8, 9. 



Anatomisk -histologisk Undersøgélse. Ved Tversnil af 



Kropshuden viser denne sig at beståa af et ydre Epithel, 

 dannet af Oylinderceller med deres lidt aflange Kjerne 

 og et rundt Kjernelegeme. Indenfor dette er et temmelig 

 bredt Bindevævslag, Tab. XXIV, Fig. 7 a, hvori tindes for- 

 mlen Bindevævslegemer og Ernæringskanaler i stor Mængde, 

 Tab. XXIV. Fig. 7 b. c, indleirede større og mindre Sand- 

 korn, der ere trængt igjennem hele Bindevævet lige til 

 dets indre Flade. Tab. XXIV. Fig. 7 d. men ligge dog 

 saa spredte, at der kan være større Mellemruin. hvori del- 

 ingen saadan Indleiring af fremmede Legemer tinder Sted, 

 og i disse Mellemrum sees et bredt Belte af Ringmuskler, 

 som indtage Midten af Bindevævslaget, Tab. XXIV. Fig. 

 7 e; Tab. XXV, Fig. 1 a, Imellem den indvendige Flade 

 af Bindevævet og Endothelet, der bestaar af temmelig 

 smale, cilierende Cylinderceller, Tab. XXIV. Fig. 7 /; 

 Tab. XXV, Fig. 1 6, ligger det sædvanlige Muskellag, som 

 heller ikke hos denne Art er stærkt repræsenteret. 



Der er 18 Macrosepta og ligesaa mange Microsepta, 

 eller om man vil 18 Septapar. Macrosepta, som ere fuld- 



The polyps rise up like columns from the sarcosoma; 

 they are eylindrical and a little eonstricted at the middle 

 (Pl. VI. tigs. 7. 8). The column is encrusted with sand; 

 it measures about 20""" in height. ti""" in breadth at the 

 base. 6 — 7""" broad at the nppermost extremity, and 4""" 

 Innad at the middle. When the polyp is retracted the 

 uppermost extremity appears truncated, but with a little 

 depression in the middle and a rounded margin carrying 

 is radii (Pl. VI. fig. 9). When the polyp is extended, 

 these radii form the same nuniber of encrusted ribs. which 

 extend themselves a small piece down the body and be- 

 tween which there is a pretty broad bare area iPl. VI. 

 tigs. 7, 8; Pl. XXV. tig. 5 a). The oral disc is almost 

 Hat. and folded. The folds issne from the slightly ohlong 

 niouth towards the periphery. 



Tlie tentacles are pretty Long aud are placed in 3 

 series: they are thick at the base lint terminate conically 

 acuminated. The outermost series contains IS and the 

 second series 16, only occasional specimens contaiiiing 

 18 tentacles: in both those series the tentacles are about 

 uniform in length : but the third, innermost series, lias 

 only ti tentacles. and they are both the longest and the 

 thickest. almost as long as the oral disc is broad. 



When the encrusted saml has lieeu partially scraped 

 away. 18 longitudinal furrows are observed upon the sur- 

 face of tlie body: these are placed close to each other 

 and are only separated by a tine. lighter- coloured line. 

 The colour. The encrusted portion of the body is greenish- 

 yellow, lint when the animal is extended almost yellow, 

 having a somewhat greenish play of colour at the base 

 only. The oral disc is faint brick-red, with darker folds 

 around the oral aperture. The tentacles are mure intensely 

 red than the oral disc. but are somewhat paler in colour 

 at the extremities (Pl. VI. tigs. 7. 8, 9). 



Anatomo-histologicnl Investigation. In a transversal 

 section of the integument of the body. the integument 

 shows itself to consist of an external epithelium formed 

 of cylinder-cells with their slightly oblong nuclei and a 

 roitnd nucleus-corpnscle. To the inside of tliat there is a 

 rather broad laver of connective-tissue (Pl. XXIV, fig. 7 a), 

 in which are found, besides connective-tissue corpuscles 

 and nutritory ducts in great abundance (Pl. XXIV. fig. 

 7 /;. <•), larger and smaller grains of sand entrenched ; 

 these have forced themselves through the entire body of 

 the connective-tissue, quite to its inner surface (Pl. XXIV. 

 tig. 7 il) but are. vet. placed sn scatteredly, that there mav 

 occur great intervals in which no such entrenchment of 

 foreign bodies takes place, and in these interspaces a 

 broad belt of annular muscles is observed occupying the 

 middle of the connective-tissue laver (Pl. XXIV. fig. 7 e; 

 Pl. XXV. tig. 1 a). Between the inner surface of the 

 connective-tissue and the endothelium, which consists of 

 rather narrow eiliating cylinder-cells (Pl. XXIV, tig. 7 /; 

 Pl. XXV, rig. 1 b). lies the usual muscular laver, which 

 is not either in this species strongly represented. 



There are 18 macrosepta. and the same nuniber of 

 microsepta or. as we may say, 18 pairs of septa. The 



