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XVII. On three new Species of Metacrinus. By P. Herbert Carpenter, D.Sc, 

 Assistant-Master at Eton College. With a Note on a new Myzostoma, by Prof. 

 L. von Graff, Ph.D. (Communicated by Br. W. B. Carpenter, F.B.S., F.L.S.) 



(Plates L.-LII.) 



Read 5th June, 1884. 



TlIE dredgings of the 'Challenger' at four stations in the Western Pacific and the 

 Malay Archipelago yielded ten species of a remarkable new Crinoid allied to Penta- 

 crinus. Most of these were drawn for the Export on the Stalked Crinoids, under the 

 superintendence of the late Sir Wyville Thomson ; and when the collection came into 

 my hands after his death, I found the name Metacrinus in his handwriting upon a proof 

 copy of one of the plates. This name is consequently employed throughout the ' Chal- 

 lenger ' Reports, in which the peculiarities of the genus are fully described. I have else- 

 where noticed the one which is most obvious at first sight as specially distinguishing it 

 from Pentaerinus*, viz. the presence of four, or even of sis radials, instead of three only. 



The other special marks of the genus are : — 1. The large size and somewhat cuboidal 

 form of the basal joints of the lower pinnules ; 2. The derivation of the ambulacra of the 

 lowest pinnules, borne on the outer radials, either directly from the peristome or from 

 the five primary ambulacra proceeding from it ; 3. The modification of the supranodal 

 stem-joints, as well as in most cases of the infranodal joints. All these characters are well 

 shown in the three species described in the following pages. 



The fine species for which the name Metacrinus rotundus is proposed (PI. L. fig. 1) 

 was dredged at a depth of 70 fathoms in Sagami Bay, Japan, by Br. L. Boderlein, the 

 Conservator of the Natural History Museum at Strassburg, in the year 1881 1- He 

 has been kind enough to intrust it to me for description, together with a considerable 

 variety of Comatuhe (both Antedon and Actinometra), which he found to be extremely 

 plentiful in the same locality. These will be considered later; but I would here record 

 my indebtedness to Br. Boderlein, and beg him to accept my cordial thanks for his 

 kindness. 



A fine Myzostoma, which I found attached to the Metacrinus, is figured and described 

 by my friend Prof. L. von Graff, of Graz. I could find none of these parasites upon the 

 Comatulce, nor were there any loose in the spirit in which they were preserved. 



The two other species of Metacrinus have been for some years in the collection of my 

 friend Mr. Charles Stewart, F.L.S. He obtained them from the officers of the Eastern 

 Telegraph Company at Singapore, where they were brought up in the process of picking 

 up a cable for repair. They were sent home in spirit ; but, by some unfortunate blunder 

 on the part of an ignorant clerk, were taken out and dried upon their arrival in this 

 country. The natural result was, in the case of Metacrinus superbus, that a considerable 



» Bull. Mus. Comp. Zool. vol. x. 1882, p. 1G7. 



t " Fauuistiseho Studion in Japan, Enoshima und die Sagami-Bai," Areuiv fur Naturgesch. 49 Jahrg. p. 119. 

 SECOND SERIES. — ZOOLOGY, VOL. II, 65 



