2y8 SoNf/icr/i Cross. 



Since C nil >c's ainpUHcatiou of the scope of the genus Tlielepua 

 there has been a tendency to drop the name Neotth ]\Ialmgren. It 

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

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

 antardica, Mclnt.,^ and a Thdepiis antardicus, Kbg., which are two 

 (liflerent species.^ "Whenever a species of Thdepus, s. ampl, is 

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

 is, " Is it not a Kcottls ? " 



1?). TlIELErUS ANTAEGTICUS. 



(Pl. XLV., fig. 6.) 



Thelepus antarcticus, Kinberg, J. Gr. H., 1866, ' Annulata Nova,' Ofv. Ak. Fork., 

 \). 345. 



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

 Polychaeta recently examined by Prof. Ehlers ^ contained this 

 highly characteristic species. Xot only is it a true Thdepus, s. str., 

 but it is proliably co-specific with the northern type, Thelepus 

 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, 3i 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 antardica, Mcintosh, 1876, = NeoHis sj)edabiHs, Yerrill, 1875, 

 = Thclepns spedabilis (Verr.), Ehlers, 1897. 



- Unless I am quite mistaken, '^L !Mal;iq\iin (1804, ' Annelides . . . de la goclette 

 MeWa^ Rev. hio?. Nord Fnuire, VT., r. 418) complet' ly cunfiised them, and I do 

 Uut know what species he ii;id before him. 



^ Ehlers, E., 1807. ' Polychaeten.' Ergebnixse Eamburg. magalhnensisdien 

 Samin'ireise, 11th Lief. 



Ehlers, E., 1000. ' Magellanische Anneliden der schwedischen Expedition.' 

 Narhr. (fes. fhittimieu. Heft 2, p. 206. 



Killers, E., 1001. 'Die Anneliden der Sammlung Plate.' ' Faum Chilensis,' 

 Pd. II., Heft 2, p. 251 (Suppt. V., ZooJ. Jahrh.). 



