134 



5 — 57a Gange i Totallængden; den første Straale i Iste 

 Dorsal udgjorde l /s ai " Hovedlængden. Afstanden mellem 

 Snudespidsen og 2den Dorsal indeholdtes omtrent 3.r> Gauge 

 i Totallængden. Skjælbeklædningen var endnu ikke fuld- 

 stændig, idet den paa Legemets forreste I >el ojensynlig 

 endnu blot var i Frembrud. At M. argentata blot er 

 en Ungform, er især paa Grund af det sidgtnævnte Factum 

 øjensynligt, og det ligger vistnok nærmest at antage den 

 for Ingen af 0. " reinhardi. Dette Spørgsmaal kan ikke 

 afgjøres, førend sikre Ungdomsstadier af de 2 nærstaaende 

 Arter. 0. reinhardt og 0. ensis, blive kjendte. 



Viser det sig altsaa i Fremtiden, at Reinhardts Mo- 

 tella argentata udgjør Ungformen af 0. reinhardi, vil Ar- 

 tens rette Navn følgelig blive Onos argéntatus,, (Reinli.) 

 1838. 



. Deu uævnte anden Art, Onos ensis, er den. som 0. rein- 

 ha/rdi i sin udvoxede Stand utvivlsomt staar nærmest. 0. 

 ensis er ligeledes en grønlandsk Form. og opstilledes af 

 Reinhardt (samtidigt med Motella argentata) i Overs. 1835 

 — 36 af det oftere nævnte Selskabs Forhandlinger, 6 Del. 

 p. CX, og senere i 7de Del. p. 116 og 128 (Kbhvn. 1837), 

 efter 2 Individer, der i noget beskadiget Stand i ] 834 vare 

 udtagne af Ventrikelen af en Cystophora cristata ved Omenak 

 (70° N. B.). 



Deu af Reinhardt paa de ovenanførte Steder givne 

 korte Characteristik er dog saa ufuldkommen. at Dr. (Jiin- 

 ther ikke deraf bar kunnet opstille nogen Diagnose, og 

 Arten lindes derfor i 1862 i hans Cat, Fish. Brit. Mus. 

 ikkeoptagen som selvstændig Art (vol. 4. p. 366). De 2 

 originale Exemplarer. der endnu opbevares i det zoologiske 

 Musæum i Kjøbenhavn, ere fremdeles, saavidt vides, de 

 eneste, som existere. og de have hidtil ikke været Gjenstand 

 for nøjagtigere Undersøgelsé og BeskriTelse. Ingen af Ar- 

 terne har hidtil været afbildet. 



Ved den flygtige Gjennemgaaelse af denue og de øv- 

 rige nærstaaende Former, som jeg ved Dr. Liitkens Vel- 

 villie havde Lejlighed til at foretage i October 1878, viste 

 det sig strax. at 0. ensis og 0. reinhardi ere fuldkommen 

 distincte, om end beslægtede Arter. De mest iojnefaldende 

 Characterer hos . 0. ensis ligge i den stærkt forlængede 

 Iste Straale i Iste Dorsal, det mindre Hoved, og den sva- 

 gere Tandvæbning, Totallængden hos de 2 Individer var 

 omtrent 310""" oe 392'""'. 1 



1 Onos ensis, (Reinh.) I83.'i — 36. 



Overs. 1835—36, Kgl. D. Vid. Selsk. STaturv. Math. Afh. 6 Del, 

 p. CX. Kbhvn. 1837 ils;;;, 36). 



• , Skjægtraade; Hovedet indeholdes omtrent •<'' , Gang> i Totallæng- 

 den. tstt striml: i 1st, Jhus,,/ lang, omtrent af Hovedet» Længde. Tova- 

 demt forholdsvis svagt og ensartede. Anus ligger midt mellem Snudespidsen 

 og Begyndelsen af Caudalen. Afstanden fra Snudespidsen til 2den Dorsal 

 indeholdes -V. 7 Gang* i Totallængden. 



2 1). 59; A. 45—46; P. 22—23. 



Til Sammenligning kan vedføjes følgende Maal af et Par om- 

 trent lige store- Individer af de 2 Artei begge fra MSisæel i Kjøben- 

 havn. 



length of the bead bears the proportion of 5 — 5 x /o. First 

 ray in first dorsal one-third of the length of the head. 

 Distance from point of snout to second dorsal is to total 

 length as 1 to 3.5. The scales not yet fully developed; 

 on the anterior part of the body indeed almost incipi- 

 ent. Hence, M. argentata must represent one of the 

 earlier stages of growth, in which case it comes nearest 

 to 0. reinhard/. This question cannot, however, be de- 

 cided until the stages through which the two closely 

 related species, 0. reinhardi and ' 0. ensis, pass before 

 reaching maturity, have become known. 



Should future researches show that Reinhardts M. 

 argentata is merely 0. reinhardi in an early stage of dev- 

 elopment, the name of the species will be Onos argentatus, 

 (Reiuh.) 1838. 



Onos ensis is unquestionably the species presenting 

 the- closest resemblance to 0. reinliardi in its adult stage 

 of development. 0. ensis is likewise a Greenland form; it 

 was described by Reinhardt (along with Motella argen- 

 tata) iu Overs. 1835—36, Kgl. D. Vid. Selsk. Afh.' D. 

 6, p. CX. and subsequently in Part 7. pp. 116 and 128 

 (1837). his specimens being two individuals, in a some- 

 what mutilated condition, which had been taken in 1834 

 from the stomach of a Oystophora cristata, near Omenak. 

 in lat. 70° N. 



The brief characterisation furnished by Reinhardt is 

 very imperfect however, so much so indeed that Dr. Gunther 

 could not elaborate from it a diagnosis; and the species 

 figures as undetermined in his "Cat. Fish. Brit. Mus." (vol. 

 4, p, 366). published 18(52. The two original individuals 

 still preserved in the Zoological Museum in Copenhagen, 

 are the only specimens known to exist, and up to the pres- 

 ent time they have not been accurately examined aud de-' 

 scribed. Neither of the species has hitherto been figured. 



The cursory examination of this and the other nearly 

 related forms which, thanks to the kindness of Dr. Liitken, 

 an • opportunity was afforded me of making in October 1878, 

 conclusively proved the specific distinction existing betw r een 

 the congeners 0. ensis and 0. reinhardi. The most conspicu- 

 ous characters in O. ensis are the produced first ray in 

 the first dorsal tin. the small size of the head, and the feeble 

 dentition. Total length in the two specimens, respectively 

 310""" and 392""". ' 



1 Onos ensis, (Reinli.) is:;:, — 36. 



Overs. 1835—36, Kyl. I). Vid. Selsk. Naturv. Math. Afh. 6 Del, 

 p. ('X, Kbhvn. 1s:;t (1835—36). 



Threi barbels; length of head is to t>>tul length as 1 to -' ,i ' 4 . First 

 rati in 1st dorsal produced, its length equalling that af the load. Troth 

 comparatively feeble, and uniform. Tin vent placed midway between the 



snarl and llo ram no no, no at of tin oaiolal fill. Jtista/irt from point of 



Snout to 2nd dorsal is to total l' nail/ os 1 la 3.7. 



2 J>. M): A. 45—46; /'. 22—23. 

 For comparison arr appended measurements of two individuals, 

 aboul equal in size, of the two species — both specimens preserved in 

 the Zoological Museum in Copenhagen. 



