126 



Slægtskarakter. 



Mardøllider med fast, inkrusteret Hud, endodermale 

 Cirkulærmuskler ; Macrosepta fuldstændige, bærende Genera- 

 tionsorganer og Mesenterialfilamenter, Microsepta ufuld- 

 stændige, golde. En Svælggrube. Adskilt Kjøn. 



Artskarakter. 



Legemet bægerformet, 35™"' langt, 20'"™ bredt foroven ; 

 den smale Basaldel omtrent 5""" bred. stærkt inkrusteret 

 af Sand. Kroppens øverste Rand forsynet med 18 blad- 

 formede, inkrusterede Kibber, strækkende sig til Mund- 

 skivens ydre Rand. Imellem Ribberne er Huden nogen, 

 ligesaa Mundskiven, der er plan, forsynet med 18 fine 

 Folder, udgaaende fra den noget fremstaaende Mund imod 

 den indre Tentakelrække. En lidet udpræget Gonidiefure. 

 Tentaklerne i to Rækker. slanke , længere end Skivens 

 Bredde. 18 i liver Raekke, de i den indre længst. Farven: 

 Kroppen er let brunrød, næsten teglstensrod, Tentaklerne 

 lysere, brunrøde; Mundskiven endnu lysere end Tentaklerne. 

 og omkring Mundskivens ydre Rand, lige ved den indre 

 Tentakelrække, en smal, lys, rosenrød Ring. Paa de unge 

 Polyper ere Farverne noget intensere. 



Epizoanthus arborescens, n. sp. 



Tab. VI, Fig. ii: Tal.. XXIV, Fig. 1 — 4. • 



Coenenchymet er tyndt, membranost udbredt snart 

 paa en større eller mindre Sten. snart spundet om tynde 

 Gjenstande, saasom Serpularør og andet lignende, Tab. VI, 

 Fig. 6; Tab. XXIV, Fig. 1 a. Fra dette Coenenchym 

 reiser flere Polyper sig dels [lodret, dels mere krybende, 

 hvorved hele Kolonien faar et grenet Udseende, Tab. VI, 

 Fig. 6; Tab. XXIV, Fig. 1. 



Polyperne ere kolleformede, og de fuldvoxne Indivi- 

 der 35™"' lange med en forholdsvis meget smal Basaldel. 

 kun 5™™ bred, imedens den øverste Ende er 12 m ™ bred. 

 Hele Legemet er inkrusteret af mer eller mindre grov 

 Sand, der dog ikke danner et tykkere Lag end at, naar 

 Dyret er udstrakt og i fuld Vigør, den hvickøde Hud 

 skinner igjennem. Opimod Kroppens øverste Rand sees 

 16 temmelig lange, lancetformede Ribber, der vende deres 

 spidse Del mod Mundskiven, Tab. VI, Fig. 6 b, og 'som, 

 naar Tentaklerne ere indtrukne, bidrage til at give den 

 øverste, afrundede Kropsdel et straalet Udseende. 



Mundskiven er temmelig flad og fint foldet, og Munden 

 er næsten rund. Tentaklerne ere retraktile, sidde i 2 

 Rækker, 16 i hver; de ere Lengere end Mundskivens Bredde. 



Generie characteristics. 



Mardollidæ with finn, encrusted integument; endo- 

 dernial circular muscles. Macrosepta perfect, carrying re- 

 productive organs and mesenterial filaments. Microsepta 

 imperfect, sterile. A gullet-groove. Separated sexes. 



Specific characteristics. 



The body chalice-formed,' 35""" in length, 20""" in 

 breadtb at the top; the narrow basal part about 5""" in 

 breadth, strongly encrusted with sand. The uppermost 

 margin of the body furnished with 18 foliform, encrusted 

 ribs. extending themselves to the outer margin of the oral 

 disc. Between [the ribs the integument is bare, also the 

 oral disc is bare; this last is plane, furnished with 18 fine 

 folds issuing from the somewhat projecting mouth towards 

 the inner tentacular series. A little-distinguished gonidial- 

 groove. The tentacles in two series, slender, longer than 

 the breadth of the disc, 18 in each series, those of the 

 inner series being longest. Tlie rolour. The body is a 

 light brownish-ied almost brick-red, the tentacles lighter 

 colourecl brownish-red : the oral disc still lighter in colour 

 than the tentacles, and round the outer margin of the 

 oral disc. elose to the inner tentacular series, there is a 

 narrow. light-coloured rose-red annulus. In the young 

 polyps the colours are somewhat more intense. 



Epizoanthus arborescens. a. sp. 



PL VI. fig. ii; Pl. XXIV. tips. 1—4. 



The sarcosoma is thin and membranaceously expanded, 

 sometimes over a greater or a smaller stone, or sometimes 

 twined round a small object such as a serpula-tuhe or 

 similar object (Pl. VI, fig. 6; Pl. XXIV, fig. 1 a). From 

 this sarcosoma several polyps rise up, sometimes erect, some- 

 times somewhat trailing, producing a ramificated appearance 

 in the entire colony (Pl. VI, fig. 6; Pl. XXIV. fig. 1). 



The polyps are claviform; the fully adult individuals 

 measure 35'"'" in length, and have a, relatively, very narrow 

 basal part. only 5'""' in breadtb, while the uppermost 

 extremity measures 12™'" in breadth. The entire body is 

 encrusted with more or less coarse sand, which does not, 

 however. form a thicker laver than, when the animal is 

 extended and in full vigour. permits the whity-red integu- 

 ment to shine through it. Towards the uppermost margin 

 of the body 16 rather long, lanceolate ribs are observed; 

 these turn their acuminate portion towards the oral disc 

 (Pl. VI, fig. 6 &), and when the tentacles are retracted 

 they contribute to impart to the superior, rounded portion 

 of the body a radiate appearance. 



The oral disc is rather flat, and finely folded ; the oral 

 aperture is almost circular. The tentacles are retrUctile 

 and situated in two series, 16 tentacles in each ; they are 



