278 South cm Cross. 



Since Grube's amplification of the scope of the genus Tlielcpus 

 tliere has been a tendency to drop the name Ncottis Mahngren. It 

 can be shown, I think, in several ways that this is ill-advised, but 

 for the present it is sufficient to point out that there is a Neottis 

 antarctica, Mclnt.,^ and a Thcleims antardiais, Kbg., which are two 

 different species.^ Whenever a species of Thelepus, s. ampl., is 

 recorded from any locality, the first question that rises to my mind 

 is, " Is it not a Neottis ? " 



13. TlIELEPUS ANTARCTICUS. 



(PI. XLV., fig. (i.) 



Thelepus antai-cticus, Kinberg, J. G. H., 1866, ' Annulata Nova,' Ofv. Ah. Fork., 

 p. 345. 



It is noteworthy that not one of the three collections of Antarctic 

 Polychaeta recently examined by Prof. Ehlers ^ contained this 

 highly characteristic species. Not only is it a true ThcUptis, s. str., 

 but it is probably co-specific with the northern type, Thelejms 

 cincinnatus (Fabr.). 



One fragment, comprising the head and thirty setigerous segments, 

 upwards of 2 inches long, was dredged off Cape Adare in 8 fathoms, 

 January 17, 1900. 



The fore-part of the body or thoracic region comprises approxi- 

 mately the first twenty-five setigerous segments, which differ from 

 the abdominal segments in their greater girth, but not in respect of 

 the parapodial armature. 



A mid-thoracic segment measures 7 mm. crosswise by 2 mm. 

 lengthwise ; an abdominal segment, 3^ mm. x 4 mm. ; so that an 

 average abdominal segment is equal to half the width and twice the 

 length of a typical thoracic segment. 



The entire dorsal surface is characterised by a rich glandular 

 pustulose structure which still preserves a slimy surface. The 



^ Neottis antarctica, Mcintosh, 1876, = Neottis spectahilis, Verrill, 1875, 

 = Thelepus spectahilis (Verr.), Ehlers, 1897. 



^ Unless T am quite mistaken, M. Malaquin (1804, ' Annelides . . . de la goelette 

 Melifa,'' Bev. hioh Nord France, VI., ]\ 418) completely confused them, and I do 

 not know what species he had before him. 



^ Ehlers, E., 1897. ' Polychaeten.' Ergehnisse Hamburg. magaJJiaensischen 

 Sammelreise, 11th Lief. 



Ehlers, E., 1900. ' Magellanische Anneliden der schwedischen Expedition.' 

 Nadir . Ges. Gottingen, Heft 2, p. 206. 



Ehlers, E., 1901. ' Die Anneliden der Sammhmg Plate.' ' Fauna Chilensis,' 

 Ed. II., Heft 2, p. 251 (Suppt. V., Zool. Jahrh.). 



