— 22 — 



south-eastern Pacific and remembering the sentence « praestat 

 distinguere quam confundere », I think it ought to be preferred 



— at least until a number of spécimens from that part of the 

 Pacific are at hand — to consider T. obtusifrons, G. O. S., as a 

 species having the latéral denticles mentioned obsolète or want- 

 ing, maintaining the Atlantic T. vulgaris as a separate species, 

 in which those denticles are well developed. ■ — On the Atlantic 

 material referred by Ortmann to T. obtusifrons a few words 

 are said above in « Remarks » on T. œqualis. 



B. Carapace without latéral marginal denticles. 



Thysanopoda acutifrons, Holt & Tatt. 



Thysanopoda acutifrons, Holt & Tattersall, op. cit., p. 102 

 and p. 134. (Immature spécimens). 



Thysanopoda pectinata, H. J. Hansen, Bull. Muse'e Océanogr. 

 n° 3o, p. 16, fig. 12 (Not T. pectinata, Ortm.) 



During the period 1 895-1904 the Copenhagen Muséum 

 gradually obtained a good number of spécimens of a large, 

 clumsy species from various localities in the boréal area of the 

 Atlantic. I had referred this species to T. pectinata, Ortmann, 

 because it agrées well with the figure given by that author and 

 as to most particulars with his rather brief description. In the 

 Monaco material I found 2 spécimens from station 1639 of the 

 same species ; consequently 1 referred them to T. pectinata 

 and published some notes accompanied with a figure. But while 

 dëtermining the Monaco material from earlier years, I met with 

 a single large spécimen which differs sharply from the species 

 interpreted by me as T. pectinata in the shape of the rostrum 

 and in shàpe and armature of the lobe from first antennular 

 joint. In both particulars, and especially in the armature of the 

 lobe, this spécimen agrées so well with Ortmann's description 



— though not with his figure — of T. pectinata that it must be 

 referred to this species. The spécimens referred in my former 

 paper to T. pectinata belong therefore to a différent species, but 

 fortunately it is not necessary to create a new name. Some 



