74 TH. MORTENSEN, (Schwed. Stidpolar-Exp. 



Among the material from the Hamburg Museum there is a specimen, labelled 

 Patagonian Bank, 46° S., 60 fms., whose tridentate pedicellariae differ somewhat from 

 those of the typical form (PI. XIX. Fig. 41); in this specimen also a 4-valved pedi- 

 cellaria was found. The latero-anal fasciole is strongly developed, while the anal 

 tubefeet are less developed than in the typical form, there being only 2 on one side 

 and 1 on the other. Perhaps this specimen is the representative of another variety 

 (or species?). The scanty material in hand does not allow me to form a definite opi- 

 nion thereon. 



The species was taken by the Swedish South Polar Expedition at the following 

 stations, all off South Georgia: 



Stat. 18 (54" 1 5' S. 36 '25' W. 250 m.). 2 specimens. 



s 22 (54 17' S. 36 28' W. 75 m.). Numerous specimens of all different sizes. 



» 23 (54 c 23' S. 36 26' W. 64 — 74 m.). Several small specimens. 



» 30 (54°24' S. 36 5 26' W. 125 m.). 1 specimen. 



» 31 (54°24' S. 36 22' W. 210 m.). 1 specimen. 

 32 (54 24' S. 36°22' W. 195 m.). 4 specimens. 



» 33 (54 : '22' S. 36'28' W. 22 m.). 1 small specimen. 



» 34 ( 54 1 1 ' S. 36 18' W. 252 — 310 m.). Several small specimens. 



The var. bidens occurs among the specimens from the Stations 22 and 23. 

 By the Fuegian Expedition a small specimen of A. cavernosus was taken at 

 52°38' S 70 0 W. 46 m. — Among the material received from the Hamburg Museum 

 there are some specimens from the Magellan Strait and one from Juan Fernandez. 



The species is as yet known with certainty only from the Southern Extremity 

 of South America (Magellan Strait, off Rio Gallegos), further from South Georgia 

 and Juan Fernandez. Probably it will prove to occur a considerable way north along 

 the Atlantic as well as along the Chilian Coast, as also at the Falkland Islands. 

 On account of the confusion which has hitherto obtained in the species of the genus 

 Abatus the numerous indications of the occurrence of -iHemiaster cavernosas* at Ker- 

 guelen, the Antarctic Coast etc., are not to be taken as certain, though it is highly 

 probable that e. g. the localities »off La Plata», the Falkland Islands, will prove cor- 

 rect — whereas it will most probably be found that all the indications of its occur- 

 ring at the Kerguelen-group are founded on a confusion with A. cordatus. — The 

 bathymetrical range of the species as hitherto known with certainty is from shallow 

 water to about 300 m. 



The collection of the Swedish South Polar Expedition contains an excellent 

 series of developmental stages of A. cavernosas, from the embryos within the mar- 

 supium to the fullgrown specimens. A few young stages of Abatus cordatus have 

 been described and figured (under the name of iHemiaster cavemosus») by A. AGAS- 



