127 



især ere ile i den inderste Række meget lange. Kurven: 

 Den inkrusterede Del af Kroppen er graa, spillende lidt i 

 det Grunne. Mundskiven er næsten hvid, med et svagt 

 rødligt Skjær. Tentaklerne ere bleg rosenrøde, Tab. VI, 

 Fig. »•• 



Anatomisk -histologisk Unclersogelse. Kroppens Hud 

 har et ydre Epithellag, bestaaende af Cylinderceller med 

 deres afiange Kjerne, Tab. XXIV, Fig. 2 a, indenfor hvilket 

 er et ikke meget bredt Bindevæv (Mesoderm), 'lab. XXIV, 

 Fig. 2 b, der ligefra Ectodermet til Entodermet er saa- 

 godtsom ganske opfyldt af uorganiske Bestanddele — Kvarts- 

 stumper, Sandkorn, Skjæl af Foraminiferer, Kiselnaale o. s. v. 

 Binde vævet er derved betydeligt reduceret; kun hist og her 

 sees enkelte Lameller, der ligge imellem de fremmede 

 Legemer, ligesom der opimod Mundskiven, hvor Inkrusta- 

 tionen er mindre kompakt, iagttages enkelte Masker, der 

 ogsaa ere opfyldte, Tab. XXIV. Fig. 2 c. Henimod Binde- 

 vævets indre Flade sees paa enkelte Steder Ringnraskel- 

 fibre, der ere endog meget spredte. Tab. XXIV. Fig. 2 </. 

 men samle sig til en stærk Muskel paa Mundskiven. imedens 

 de ganske forsvinde ned imod Polypens Grunddel. 



Det har ikke været muligt at opdage de for Zoan- 

 therne saa særegne store Celler (Zellhofe) i Bindevævet, 

 ligesom Bindevævslgemerne synes at være sparsomme; men 

 som tidligere anført, Bindevævet er saa optaget af frem- 

 mede, uorganiske Bestanddele, at dets Struktur vanskelig 

 kan udgranskes, Tab. XXIV, Fig. 2 e. 



Paa Bindevævets indre Flade ligger det sædvanlige 

 Muskellag, der dog ikke er meget fremtrædende og bestaar 

 af Tver- og Længdemuskler, hvoraf de sidste ere mest 

 udviklede. Tab. XXIV, Fig. 2 f. Hele Gastrovascularhul- 

 heilens Vægge ere beklædte med et Endothel, der dannes 

 af cilierende Cylinderceller. 



Der er 16 fuldstændige Septa og ligesaa mange ufuld- 

 stændige, eller, om man vil. 16 Par Septa, som dannes af 

 16 Macrosepta og 16 Microsepta, Tab. XXIV, Fig. 3, (paa 

 et Exemplar var der 18 Septapar). Af disse Septapar er 

 der 2, som maa betragtes som Retningssepta, nemlig et . 

 Par, der bestaar af Macrosepta og ere fæstede til den Del 

 af Svælgroret, paa hvis indre Flade Svælggruben tindes, 

 og angiver Bagsiden, Tab. XXIV. Fig. 3 a, og det andet 

 Par, som bestaar af Microsepta og vender til Rygsiden, 

 Tab. XXIV, Fig. 3 b. 



Heller ikke paa denne Art tinder jeg, at Benævnelsen 

 Septapar er stærkt begrundet i de naturlige Forholde; thi 

 lier. ligesom hos Mardøll, tåge ei alene Septaerne ikke 

 deres Udspring fra samme Sted (saaledes udgaa de fuld- 

 stændige Septa, Macrosepta. fra Bunden af Gastrovascular- 

 hulheden, imedens de ufuldstændige. Microsepta, tåge deres 

 Begyndelse lidt længere oppe paa Kropsvæggen) , men de 



longer than the breadth of the oral disc. and in the inner 

 series, especially, they are much longer. The colour. The 

 encrusted portion of the body is grey, with a play of 

 greenish colour. The oral disc is almost white with a 

 faint reddish tinge. The tentacles are pale rosy-red (Pl. 

 VI. fig. 6). 



Anatomo-histoh//i<iil Investigation. The integument of 

 the body has an external epithelial layer consisting of 

 cylinder-cells with their oblong nuclei (Pl. XXIV, fig. 2 a), 

 inside of which there is a not very broad connective-tissue 

 (mesoderm) (Pl. XXIV, fig. 2 b), which is. quite from the 

 ectoderm to the entoderm, almost completely occupied by 

 inorganic substances, such as fragments of quartz, grains 

 of sand, shells of foraminifera, needles of silicon, etc. The 

 connective-tissue is, therefore, considerably diminished in 

 quantity ; only here and there a few lamellæ are observed 

 lying between the foreign substances; while, also, up towards 

 the oral disc, where the encrustation is not so compact, 

 threre are observed a few meshes that are also occupied 

 (Pl. XXIV, fig. 2 c). In proximitv to the intemal surface 

 of the connective-tissue, annular muscle-fibres are observed 

 in a few places ; these are, howover, much scattered (Pl. 

 XXIV, fig. 2 cl) but collect themselves into a powerful 

 mnscle on the oral disc, while they completely disappear 

 down towards the basal portion of the polyp. 



It has not been possible to discover the large cells 

 (Zellhofe) in the connective-tissue that are so characteristic 

 of the Zoantidæ. while the connective-tissue corpuscles, 

 also, appear to be sparingly present; but. as previously 

 stated, the connective-tissue is so occupied with foreign 

 inorganic substances, that its structure can with difficulty 

 be investigated (Pl. XXIV, fig. 2 e). 



Upon the internal surface of the connective-tissue the 

 usual musculous layer lies, but is, however, not very 

 prominent, and consists of transversal and longitudinal 

 muscles, of which the last-named are the most developed 

 (Pl. XXIV, fig. 2 f). The entire walls of the gastro- 

 vascular cavity are clad with an endothelium formed of 

 ciliating cylinder-cells. 



There are 16 perfect septa and the same number 

 of imperfect ones, or, as we may say, 16 pairs of septa, 

 formed of 16 macrosepta and 16 microsepta (Pl. XXIV, 

 fig. 3); in a single specimen there were 18 pairs of 

 septa). Of these pairs of septa, there are two pairs which 

 must be regarded as directive septa; thus, one pair that 

 consists of macrosepta, and which are secured to the portion 

 of the æsophagus upon whose inner surface the gullet- 

 groove is found, indicating the ventral side (Pl. XXIV, 

 fig. 3 a), and the other pair, that consists of microsepta 

 and face to the dorsal side (Pl. XXIV. fig. 3 b), 



Neither do I tind in this species that the appellation 

 — pair of septa — is full v warranted by the natural rela- 

 tions, as here, as in Mardoll. the septa not only do not 

 originate from the same situation (the perfect septa — 

 macrosepta — issne from the bottom of the gastro-vas- 

 cular cavity. while the imperfect septa — microsepta — 

 originate a little fart her up on the body-wall), but the 



