REVIEWS. 



ECHINOID OR CrINOID ? 



Ueber einige palaeozoische Seeigelstacheln {Timorocidabis 



GEN. NOV. UND BoLBOFOBITES PaNDER). By JOHANNES 



Wanner. Versl. Natuurk. Afdeel. Akad. Wetensck. Amsterdam, 

 xxviii, pp. 797-813, pL 1920. 



pROFESSOR WANNER kas found in tke Permian of Timor 

 -^ some eckinoderm remains wkick ke bekeves to be radicles 

 of an eckinoid, and tkerefore names Timorocidaris. In skape one 

 of tkese objects is like a muskroom, witk rounded top and skort 

 stalk. Tke alleged upper outer face is normally pustulate, but 

 sometimes smootk. Tke circular outline is sometimes modified 

 by truncations, as tkougk tkese supposed radioles kad been crusked 

 close togetker on tke test, as are tke radioles of Colohocentrotus. 

 Tke large majority (2,150 out of 2,422) of tkese bodies kave tke end 

 of tke stalk bevelled off by tkree facets, wkick meet round a small 

 central koUow. " Tke remarkable feature is tkat tkese tkree surfaces 

 are faskioned as articular facets witk a pronounced crinoid 

 ckaracter." Eack facet skows tke fulcral ridge, sejDarating an outer 

 crescentic ligament-face from tke two inner muscle-plates, wkick are 

 divided by a median groove or notck. At tke middle of tke 

 ligament-face, adjoining tke falcral ridge and opposite tke notck, 

 is a depression, wkick may indicate a more pronounced ligament- 

 scar (as Dr. Wanner interprets it) or a canal for a nerve. Some 

 of tke remaining specimens kave merely a kollow at tke end of 

 tke stalk, and Dr. Wanner believes tkat tkis kollow represents 

 one of tke facets, lie claims to kave»niaterial proving a passage 

 from one type of structure to tke otker, but kis figures are not 

 convincing. Some of tke specimens kave an ornament resembling 

 tkat of Ciclaris scrobiculata and one or two otker radioles from 

 tke Alpine Trias. 



It is possible tkat tkere are some true eckinoid radioles in tkis 

 material, but I am at a loss to understand kow tke majority witk tke 

 tkree articular facets can be interpreted tkus. Setting aside tke 

 fact tkat no suck structure kas ever been seen in tke Eckinoidea, 

 is it not obvious tkat suck facets could not kave been used for tke 

 attackment of one rigid body to a single rigid surface of wkatever 

 skape ? Eack of tkese facets must kave been attacked to a separate, 

 movable, skeletal element of similar section, i.e. witk a rounded 

 outer back and grooved inner surface. Tkat wkick was fixed as the 

 stalk, tkat wkick was movable, was tke group of structures attacked 

 to tke facets. Tkose structures must kave diverged from one 

 anotker at tke outset. 



Dr. Wanner makes a number of kypotkeses, eack of wkick ke 

 tests conscientiously and finds unworkable ; ke also exerts kimself 



