lOl) SVEN LOVEN, ON THE ECHINOIDEA DESCRIBEl) BY LINN/EUS. 



them is a verv young specimen not to be distinguished from 

 the smallest of the four typical specimens, tlie other a nearly 

 full-grown specimen, 38 mm. and 24 mm. Tliis v. Mårtens 

 is inclined to resfard as an adult E. africana Tkoschel, iu which 

 1 entirely agree. He says it attains the dimensions of 47 

 mm. and 26 mm. The difference in the relation of heioht 

 to diameter, 0,6 3 in the adult and 0,4 4 in the young, is 

 perfectly consistent with the general rule. The ambulacral 

 areola is, as visual in young specimens, very narrow, as pointed' 

 out by Troschel; the faint vstar-, observed by him, comes 

 from the somewhat retarded development of the second and 

 third series of the interradial tubercles, and is seen in the 

 young of any species. 



I have compared the original of Troschel's elaborate de- 

 scription of his Ecliinocidaris australis, a finc specimen from 

 the collection of the late Professor Wilhelm Dunker of 

 Marburg, with a specimen from Rio Janeiro sent me by A- 

 LEXANDER Agassiz as vArbacia pustulosa» and another from 

 »Three fathoms Bay» near that place, and can find no spe- 

 cific difference whatever. The habitat Australia given by 

 Dunker must be erroncous, as before said. 



The Arbacia ^randinosa of Valenciennes rests on the 

 ligures given in the Zoology of the Voyage of the Venus, 

 1836—1839, Zoophytes, Pl. XI, fig. 1 a—7i] 1846. Its descrip- 

 tion was never published. The ship touched on its voyage 

 out at Rio, and then at Valparaiso, Lima, Payta, Acapulco, 

 Monterey, New Zealand, and at other places in the Pacific 

 and Indian Oceans. The >.Zoophytes» figured, all Echinoidea 

 and Gorgonige, are for the most part from the west coast of 

 America, some from the Pacific and the Indian Ocean, and 

 one from the Falkland Islands. Agassiz and Desor in their 

 »Catalogue Raisonné» recorded the A. grandinosa A' al. as 

 present in the Paris Museum, from Peru through Gaudichaud, 

 who is also quoted for the Arbacia spathuligera and Echinocidaris 

 nigra, from Coquimbo and Payta, and who had probably col- 

 lected them all durino- his vovaoe 1830 — 1833 in the Hcr- 

 minie, as neither the Uranie nor the Bonite, on board both 

 of which he officiated as botanist, touched at Coquimbo. Ple 

 is not cited for any other habitat in the whole Catalogue. 

 Desmoulins in 1837 enumerated an E. aequituberculata from 

 Peru, apparently the same specimens that soon afterwards 



