PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 649 



The species enumerated are: 



MUR^NA.* OpHICHTHUS. 



1. M. Jielena L. 1. 0. opMs (L.) 



2. M. nebulosa. 2. 0. serpens (L.) 



3. M.picta. 3. 0. cinereus. 



4. M. annulata. 4. 0. myrus (L.) 



5. M.fasciata. 5. 0. conger {Jj.) 



6. 0. anguilla (L.) 



The first species mentioued under OphichtJms is noticed as follows: 

 " 0. oj)his : Cauda apterygia, corpore tereti, maculato. Hab. in 

 Europeo niari et Indico. 



"Synonym: Munena ophis Linn. S. N. p. 425. 



" Serpens mariuTis maculosus Will. ajyp. p. 19. 

 "Houttyu Natnral Hist. 1. D. p. 87. 

 "Blocli, p. II, p. 35, t. 154." 



As to the authorship of this paper, Dr. Liitten observes : " It is ques- 

 tionable whether the dissertation should be ascribed to the ^ Pmesid.', 

 Thunberg or to Ahl ; you will see that the contemporaneous Vahl si^aks 

 of it as being of Thunberg, without phrase, aod it is ascribed to Thun- 

 berg also by Engelmanu. Until a late time, in the Swedish universities, 

 the dissertations were written by the professor and only ' defended' 

 by the students whose name they bear. Thus often you will find that 

 a page by Eetzius or Linuieus was distributed to ten or twenty students, 

 a sheet to each, for being defended, bearing these different names on 

 their titles, but being afterwards collected and put together under 

 the name of the real author. In other instances they were written by 

 the student, when he was able to do it, and it is only to be seen from 

 the paper itself whether it belongs to the student or to the master. In 

 this special case it appears from the proemium that Ahl reallj- pretends 

 to be the author, although probably he was not." 



This appears to be the earliest attempt at subdivision of the genus 

 Murwna, the name OpMclithus being intended for all eels with pectoral 

 fins. For some group of these eels it must, of course, be retained. 



In the diagnosis of the first three species the phrase " Cauda apt ery- 

 gia" occurs, and it is to eels thus characterized, that the name (more 

 correctly spelled Ophiclitliys) is restricted by Dr. Giinther. One of ihe 

 three species, ojihis, serpens and cinereus^ must then be taken as its type. 

 Two writers, Bleeker and Poey, have attempted further to restrict the 

 genus Ophichthys. By a misapprehension, unfortunate, but easily ex- 

 l)lained, Poey has considered Munena annulata as the type of Ophich- 

 thys. As we have seen, this species is explicitly excluded by Ahl, and 



*This restriction of the Liuntean genus Munena to M. helena and its supposed con- 

 geners must, of course, take precedence over the restriction made by Blocli & Schnei- 

 der in 1801, wherein J/, anguilla was retained as the typo of Muroena, and M. helena 

 referred to a new genus, Gymnothorax. 



