horstens, bygnad, ;iro i min tanke de vigtigaste, och ega 

 tvifvelsutan betydelsen af goda genuskarakterar. Deres gil- 

 tighet som sådana anser jag tilfyllest ådagalagd iifven af 

 den omstandigheten, att hos samtliga andra havs annulata 

 ibtborsten iiro danade på samma silt eller efter sama typ 

 hos arterna inom hvarje lor ett genus almant erkand grupp, 

 ja stundom inom hele familjer. Med olikheten i horstens 

 bygnad folje alltid olikheter i djurets hela utseende och 

 organisation, åtminstone hvad de yttre anatomiske karak- 

 tererna betraffer' . 



Etter de her citerede Ord skulde man vente, at der 

 blandt Pohjnoerne fandtes en temmelig betydelig Forskjel- 

 lighed. ikke alene med Hensyn til Borsternes Bygning, 

 men også med Hensyn til Dyrenes ydre anatomiske Kjen- 

 detegn. Og dog er dette ingenlunde Tilfældet. hvad man 

 o^saa uden videre kan se af Malmgrens egne Figurer; 

 Dyrene ere hinandeii saa lige, at man neppe uden en om- 

 hyggelig detaljeret Undersøgelse er istand at skjelne dem 

 fra hinandeu ; især gjælder dette Exemplarer opbevarede i 

 Alkohol; ja Ligheden gaar saa vidt. at Mobilis, som oven- 

 for nævnt, har ment, at ikke mindre end 4 Dyr, der af 

 Malmgren ere opforte under ! 4 forskjellige Slægter, kun 

 ere Varieteter af en og samme Form. en Opfatning, som 

 P. Tauber ' ikke alene deler, men yderligere udvider der- 

 hen, at han til de 4 Dyr ogsaa foier Lænilla mollis og 

 Lænilla alba samt Lagisca rarispina — Lagisca propinqva. 

 Medens Møbius, som allerede omtalt, til Vidnesbyrd om 

 sin Opfatnings Rigtighed dog autorer Malmgrens egne Be- 

 skrivelser af de omtalte Dyr. stiller Tauber uden Bemærk- 

 niuger de af ham medtagne Dyr ind som Synonymer under 

 Harmofhoe imbricata, medens det dog skulde synes at være 

 en Undersogelse værd. om ikke de nævnte Dyr ialfald 

 kunde opføres som selvstændige Arter, om de end ikke kunne 

 henføres til egne Slægter. Men jeg maa antage, at Herr 

 Tauber ikke har seet de Dyr, han saaledes slaar sammen 

 med Harmothoe imbricata; thi den, der har seet f. Ex. 

 Lagisca rarispina kan umuligt tro. at denne og Harmothoe 

 imbricata ere samme Dyr. Man behøver ellers kun at se 

 paa Malmgrens Figur af L. rarispina for at overbevise sig 

 herom. Medens de af Møbius og Tauber sammenslaaede 

 Dyr utvivlsomt ere vel karaktiserede Arter, kunne de der- 

 med neppe med Rette henføres til særegne Slægter. Og 

 allermindst kan hertil bruges Børsterne, der hos næ- 

 sten samtlige Polynoer ere hinamlen saa lige, at det ofte 

 kan have sin store Vanskelighed at kjende dem fra liinan- 

 den. og om forskjellige Typer af Børster kan der paa 

 ingensomhelst Maade være Tale. At de dorsale Borster 

 hos somme Dyr ere tykkere eller kortere end de ventrale 

 eller omvendt, samt at de ventrale Børster ere delte eller 

 udelte i Spidsen kan ikke betragtes som forskjellige Typer 

 for Bygningen, ligesom disse smaa Forskjelligheder i Bør- 

 steformerne heller ikke give Dyrene liogen særegen Karak- 

 ter. Typen for Børsterne er den samme for alle Polynoer 

 med delvis Undtagelse kun for Mélænis Loveni og Polynoe 

 scolopendrina's Vedkommende, nemlig for de dorsale en let 



important, and must unquestionably rank as true generic 

 characters. Their validity as such is. I think, sufficiently 

 manifest from the fact of the pedal bristles in all other 

 marine Annulata having the same structure, or the same 

 type, in the species of every group constituting, as gene- 

 rally understood, a genus, nay sometimes throughout an 

 entire family. Dissimilarity of structure in the bristles is 

 invariably accompanied by general dissimilarity of appea- 

 rance and organisation, as regards at least the external 

 anatomical characters of the animal." 



From what is stated here, a considerable difference 

 might be inferred to exist between the members of the 

 family Polynoido 3 . and not. only as concerns the structure 

 of the bristles, but also with regard to the external ana- 

 tomical features of the animals. This, however, is not the 

 case, as will at once appear from a glance, at Malmgrens 

 own drawings. Indeed, unless carefully examined in de- 

 tail, it is hardly possible to distinguish between them, 

 so closely do the animals resemble one another. This ap- 

 plies more particularly to specimens preserved in spirits, 

 the resemblance in such being so great, that Mobius. as 

 previously stated, held 4 animals, established by Malmgren 

 as 4 new genera, to be merely varieties of one and the 

 same form. — a view which P. Tauber ' not only shares, 

 but found reason to extend, regarding as additional varie- 

 ties Lænilla mollis, Lænilla alba: and Lagisca rarispina 

 ( Lagisca propinqra). Mobius gives, as previously stated, 

 in support of his construction. Malmgrens own diagno- 

 ses; whereas Tauber simply refers as synonyms, with- 

 out remark, the animals in question to Harmothoe 

 imbricata. Meanwhile, admitting the establishment of sepa- 

 rate genera for the said animals to be out of the question, 

 they are possibly entitled to rank as distinct species. 

 Tauber. however, can hardly know from autopsy the ani- 

 mals he has thus confounded with Harmothoe imbricata : for 

 no one who has seen, for instance, Lagisca rarispina, can 

 possibly take that animal to be the same as Harmothoe 

 imbricata. Indeed, this is sufficiently obvious from Malm- 

 gren's drawing. Hence the animals confounded together 

 by Mobius and Tauber are beyond a doubt specifically ' 

 distinct. To the rank of genera, on the other hand, they 

 can hardly pretend; and certainly the last feature to 

 adduce as a generic character would be. if justly consi- 

 dered, the structure of the bristles, which are so remar- 

 kably alike in well-nigh all Polynoæ, that very considerable 

 difficulty is frequently experienced in distinguishing between 

 them: and as for types of bristles, there is nothing of the 

 kind, characters founded on such an assumption being 

 altogether spurious. The fact of the dorsal bristles being- 

 shorter or thicker than the ventral, or vice-versa, and that 

 of the ventral bristles being cleft or not cleft at the points, 

 cannot be regarded as typical peculiarities of structure; nor 

 do these minute differences in the form of the bristles 

 furnish the animal with any true character, generic or 

 specific. ■ The type of the bristles is the same in all 



1 Annulata daniea. 



Annulata daniea. 



