49 



ordentlig! rigt paa Bindevævslegeiner med deres Kjerne, 

 Tab. VIII. Fig. 1 a. Henimod dette Bindevævs indre 

 Flade sees et Belte af temmelig tykke, cirkulære Muskel- 

 fibre, der tildels anastomosere med hverandre, og som' have 

 et udpræget endodermalt Leie, Tab. VIII. Fig. 1 //. idet 

 Endothelet stoder nærmest til. imedens der i hele det 

 øvrige brede Lag; af Bindevævel ikke tindes Spor at' 

 Muskler. 



Der er 6 Par principale, fuldstændige Septa, hvoraf 

 •2 ere Retningssepta ; samtlige ere gidde. I ethvert af de 

 derved fremkomne (i interseptale Hovedkamre er der 3 Par 

 Septa af -M' n Orden, som dele hvert af Hovedkamrene i 4 

 Kamre af 2den Orden. I ethvert af disse Kamre er der 

 1 Par Septa af 3dje Orden, som er meget kort. Septa- 

 parrene af 2den Orden ere omtrent lige lange og strække 

 sig næsten lige hen til Svælgrøret; paa dem ere Genera- 

 tionsorganerne fæstede, Tab. VIII, Fig. 1 c, og paa 1 Exem- 

 plar var Æggestokkene saa stærkt udviklede, at .Eggene i 

 forskjellige Udviklingsstadier opfyldte Kamrene saavel af 

 Iste og 2den som af 3'lje Orden, med andre Ord. hele 

 Gastralhulheden var udfyldt med Æg, Tab. VIII, Fig. 1 d. 

 Acontierne ere fæstede Lengere nede mod Bunden af Mave- 

 hulheden. ligeledes paa Septa at 2<len Orden, og ere i tem- 

 melig stor Mængde tilstede, sammenrullede i Spiraler. 



deg har. som det vil sees. dannet en ny Familie for 

 Slægten Madoniactis, omendskjont denne i sit Ydre ligner 

 Tealiderne. men i væsentlige anatomiske Dele Sagartiderne 

 sa;i særdeles meget, at det vid kumle forsvares at henføre 

 den til dem. Slægten Tealia har saavel Gosse som Dr. 

 Andres hentørt til Familien Bunodidæ. imedens Hertwig 

 har dannet en ny Familie. Tealidæ, for den. grundet hoved- 

 sagelig paa Cirkulærmusklernes endodermale Leie. Han 

 karakteriserer Familien saaledes: ..Hexactiniæ with numer- 

 ous perfect septa. and very contractile. [moderately long or 

 short tentacles, which can be completely covered. Circular 

 muscle very strong endodermal, projecting as a thick swelling 

 into the gastric cavity." 



Familien Sagartidæ er karakteriseret af Hertwig saa- 

 ledes: ..Hexactiniæ with acontia, a strong niesodermal cir- 

 cular muscle and numerous very contractile tentacles; the 

 principal septa, or septa of the first order, univ are per- 

 fect and at the same time sterile; all the remaining septa 

 are imperfect." 



Man vil af Beskrivelsen over Slægten Madoniactis have 

 erfaret, at den efter dette hverken kan henføres til den 

 ene eller den anden af de to nysnævnte Familier, naar de 

 cirkulære Musklers Leie skal være det afgjørende. Mest 

 nærmer den sig Sagartiderne. kun Hensynet til de cirku- 

 lære Muskler har gjort, at den ikke er stillet i deres 

 Række. Ihvorvel jeg ikke. ifølge mine hidtil gjorte Under- 

 søgelser. kan tillægge de cirkulære Musklers Leie saa stor 

 Betydning som Hertwig, saa antager jeg dog. at de bor 

 komme i væsentlig Betragtning som et udpræget Karakter- 

 mærke. der muligens kan faa den systematiske Overvægt, 



Den norske Nordhavsexpedition. 1). C. Danielssen: Actinida. 



connective-tissue laver, extremely rich in connective-tissue 

 corpuscles with their nuclei i Pl. VIII. fig. 1 a). Towards 

 the inner surfare of this connective-tissue theiv is observed 

 a belt ol pretty thick circular muscle-fibres that to some 

 extent anastomose with each other, and which have a 

 distinct endodermal seat (Pl. VIII, fig. 1 />), as the endo- 

 thelium adjoins closest, whilst in the entire remainder of 

 the broad connective-tissue laver no trace of muscles is to 

 be found. 



There are 6 pairs of principal. perfect septa. of which 

 2 are directive septa; all of them are sterile. In each of 

 the (i interseptal principal chambers tbus produced, there 

 are three pairs of septa of the second order, which divide 

 each of the principal chambers into 4 chambers of the second 

 order. In each of these chambers there is 1 pair of septa 

 of the third order which are very short. The pairs of 

 septa of tlie second order are about equal in length, and 

 extend themselves almost right up to the æsophagus; the 

 organs of reproduction are secured upon them (Pl. VIII. 

 fig. 1 r), and in one specimen the ovaries were so strongly 

 developed that the ova. in various stages of development, 

 filled the chambers of the first and second as well as of the 

 third order; in other words the entire gastral cavity was 

 stuffed with ova (Pl. VIII. fig 1 &). The acontia are 

 adherent farther down towards the bottom of the gastral 

 cavity. also upon septa of the second order, and they are 

 present in råtner great ahundance, coiled up in spirals. 



I have, as will be apparent, formed a new family 

 for the genus Madoniactis. although it. in externals, re- 

 sembles the Tealidæ. and in important anatomical points 

 the Sagartidæ so very greatly, that it might well lic 

 justified if it was assigned to them. Goss, as well as 

 Dr. Andres, has assigned the genus Tealia to the family 

 Bunodidæ, whilst Hertwig has formed a new family. 

 Tealidæ, for it. based principally on the endodermal seat 

 of the circular muscles. He characterizes the family thus: 

 „Hexactiniæ with numerous perfect septa. and verv con- 

 tractile. moderately long or short tentacles, which can be 

 completely covered. Circular muscle very strong endoder- 

 mal, projecting as a thick swelling into the gastric cavity." 



The family Sagartidæ is characterized by Hertwig 

 thus: ,. Hexactiniæ with acontia, a strong niesodermal cir- 

 cular muscle and numerous very contractile tentacles; the 

 principal septa, or septa of the first order, only are perfeel 

 and at the same time sterile; all the remaining septa im- 

 perfect." 



From the description of the genus Madoniactis it will 

 be seen, that it cannot be assigned to either the one or 

 the other of the two families just mentioned, if the seat of 

 the circular muscles is regarded as the point of determination. 

 It resembles the Sagartidæ most, and only regard to the 

 circular muscles has prevented it being placed in that sub- 

 family. Although I cannot, according to my investigations 

 up to date, place such great stress on the seat of the 

 circular muscles as Hertwig does. vet I must assume that 

 it ought to be regarded as of importance as a distinct 

 characteristic trait which. possibly, may have the systematic 



