Miscellaneous. 499 



the others that they are each continued as two whitish streaks, but 

 without pores, to the periphery, and beyond this towards the mouth. 

 The pores of the same pair are united by very shallow furrows, 

 which can be seen distinctly only in particular spots. Ambulacral 

 plates at the same level as the interambulacral spaces ; the posterior 

 interambulacral space presents in its median line a very faint ridge- 

 like edge, running from the vertex to the upper margin of the anal 

 orifice. 



Length 17, breadth 13|, height 8, longitudinal diameter of mouth 

 2 millimetres. 



Hab. The island of Adenare, at the eastern end of Flores (between 

 Java and Timor). One specimen found, thrown up on the beach. 



The only species of this genus previously known (Nucleolites 

 recens, M.-Edw., from Australia) is distinguished essentially by a 

 deep furrow in the posterior interambulacral space in which the 

 anal orifice is situated, as also by its broader form, from our species, 

 in which the short channel beneath the anus is the only indication 

 of the above-mentioned furrow. We know, however, numerous spe- 

 cies, from the Jurassic, Cretaceous, and Tertiary periods, with and 

 without furrows uniting the ambulacral pores : most of them have 

 the anal orifice placed higher up ; but even in this respect the well- 

 known N. neocomensis, Ag., agrees with our species, as indicated by 

 the specimens in the Palseontological Collection here. The state- 

 ment, "anal orifice superior," or "on the dorsal surface," which is 

 to be found in most books among the characters of this genus, may 

 therefore be expressed more accurately as follows : — " Anal orifice 

 above the periphery." Desor, in his most recent elaboration of the 

 Echinides (Synopsis des Echinides fossiles, 1858), divides the genus 

 Nucleolites into two, according as the ambulacral pores of each pair 

 are united by a furrow (Nucleolites) or not (Ecki?wbrissus) . The 

 shallow, hardly perceptible furrows of the present species do not 

 justify any such division. 



I may take this opportunity of remarking that a younger specimen 

 of Oreaster armatus, Gray, described by me in the ' Monatsbericht ' 

 for January 1865, p. 156 (see Annals, p. 433) has been described and 

 figured by Mobius, under the name of Goniodiscus conifer, in the 

 ' Abhandlungen der naturwissenschaftlichen Gesellschaft zu Ham- 

 burg,' Band iv. The difference in the determination of the genus 

 is explained by the fact that (as Liitken has already stated, and as I 

 find to be the case in the Indian species, of which I have series of 

 different ages) in young specimens of Oreaster both the inferior and 

 superior marginal plates assist in forming the margin — a character 

 which is permanent in Goniodiscus and Astropecten, but undergoes 

 a change with growth in Oreaster. — Monatsber. Akad. Wiss. zu 

 Berlin, March 1865, p. 140. 



A New American Silkworm. 



After numerous experiments, Mr. L. Trouvelot, of Medford, Mass., 

 has succeeded in rearing, and in great numbers, Attacus Polyphemus, 

 Linn., and in preparing from its cocoon an excellent quality of silk, 



