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OPHIOCOMA. 



was 9.5 : 30, 16 : 68, and 19 : 93. The radial shields vary a httle in size 

 and distinctness. 



I have satisfied myself that this is the same species as the Ophiolepis 

 imbricata of MtiUer & Troschel, whose imperfect description at first led 

 me to describe it as new. 



LIST OF SPECIMENS. 



Vrhence obtained. 



Museum of Comparative Zoology. 



1 Kingsmills Islands. A. Garrett. Dried 



12-f- Kingsmills Islands. A. Garrett. Alcoholic, 



Zanzibar. 



C. Cooke. 



OPHIOCOMA Agassiz. 



Type of the Genus, 0. scolopendrina Agass. 



Disk granulated. Eadial shields covered. Teeth, tooth-papilkTe, and 

 mouth-papillae. Spines, usually from four to six ; smooth ; arranged 

 along the sides of the side arm-plates. One or two tentacle-scales. 

 Two genital slits, begimiing outside the mouth-shields. 



NOTE ON SOME SPECIES OF THE GENUS OPHIOCOMA. 



Ophiocoma dentala Mill]. & Trosch., of which the original is in the Berlin Zoological 

 Museum (No. 931), is not a good species, and seems only a middling sized Ophiocoma 

 echiiiata. The species described by Dr. Lutken as 0. dentata is quite another thing, and 

 seems to be O. brevipes (Addit. ad Hist. Oph., p. 165). 



Ophiocoma variabilis Grube (Acad. Cajs. Nova Acta, 1860) is, according to the plate 

 and the description, only a partly grown specimen of 0. Schoenleinii, or of some allied 

 species. 0. Schoenleinii itself is rather a dubious species. The originals at Berlin (Zool. 

 Mus., No. 930, and Anatom. Mus., 11561) look like some varieties of 0. erinaceus, the 

 chief difference being that most of the tentacle-pores have but one tentacle-scale. The 

 same doubts may be raised about 0. Wendtii (Berlin Zool. Mus., No. 929), whose chief 

 distinguishing marks are the absence of the second tentacle-scale on most of the joints, and 

 the peculiar form of the basal under arm-plates. It may turn out that O. Wendtii and 

 0. Schoenleinii are the same species. 



Ophiocoma tumida Miill. & Trosch. The original, in the Leyden Museum, is marked 

 " Gulf of Genoa " ; but this looks like a mistake. I do not remember to have seen any 

 Ophiocoma at all from the Mediterranean, much less one which in size and appearance 

 closely resembles O. echinata. 0. bidentata Mull. & Trosch. is plainly a worthless species, 

 and 0. M'lssonii Miill. & Trosch. probably goes in the same category. 



