212 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



AUSTROCIDARIS, gen. nov. (Latin auster, the south wind, + cidaris). 



Test flattened, .50-.60 h. d., but otherwise much as in Dorocidaris ; abactinal 

 system much more sparsely covered with miliaries ; secondaries more or less nearly 

 cylindrical and thickened at tip; primaries generally short, often less than h. d., 

 and usually smooth (in individuals where primaries are long and rough, second- 

 aries are nearly flat, so that resemblance to Dorocidaris is marked). Tridentate 

 pedicellariae wanting and globiferous pedicellariae with no end-tooth on valves ; 

 eggs and young carried by female (mortenseni?). 



Were it not for their geographical isolation it would hardly be worth while to 

 attempt the separation of these three small species from Dorocidaris, but as they 

 have the above given peculiarities in common and are probably more nearly 

 related to each other than to any other forms, it is convenient to keep them apart. 

 They are confined to the southern parts of the Atlantic and Indian oceans, their 

 known range extending from 75° W. to 90° E. longitude and from about 35° 

 to nearly 70° S. latitude. The following key is based on the examination of 70 

 specimens of nutrix and canaliculata. 



Key to the Species. 



Actinal primaries not conspicuously flat, trowel-shaped, and entire. 



Median ambulacral and interambulacral areas bare and more or less 

 deeply sunken ; interambulacral area usually with a conspicuously 

 deep vertical furrow ; vertical diameter about .55-.60 h. d. ; abacti- 

 nal system and actinostome rather small, .35-.40 h. d., about equal, 



or former smaller canaliculata 



Median ambulacral and interambulacral areas little bare, and not at all 

 sunken ; vertical diameter about .45-.55 h. d. ; abactinal system and 

 actinostome large, about .50 h. d., about equal or former larger . . nutrix 

 Actinal primaries conspicuously flat, trowel-shaped, and entire ; primaries 



long mortenseni 



Austrocidaris canaliculata. 



Temnocidaris canaliculata A. Agassiz, 1863, Bull. M. C. Z., 1, p. 18. 



Plate 1, g, fig. 3, Rev. Ech., A. Agassiz, 1873. Plate 2, figs. 1-3, Challenger 



Ech., A. Agassiz, 1881. 



Some of the differences between this species and the next have already been set 

 forth by Mortensen ( : 03), but he has entirely ignored the more important differ- 

 ences in the test and abactinal system. Moreover he has himself been led astray 

 by the remarkable diversity which this species exhibits in its color, spines, and 

 pedicellariae, and has described as a new species of Stereocidaris, which he calls 

 lorioli, the long-spined form of canaliculata, which the " Challenger " collected off 

 the mouth of the River Plate (Station 320). The Museum of Comparative Zool- 

 ogy contains one of the " Challenger " specimens from St. 320, and also a large 



