674 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxiii. 



In a large jar containing fragments of arms and stems of Meta- 

 crinus rotundus, M. angulatus., and BI. superhus^ all from the Eastern 

 Sea near Kagoshima, I found the upper part of a stem of Metacrinus 

 superhus with part of the calyx attached, and it is on this sjDecimen 

 that the following observations have been based. 



The method used in disintegrating the specimen was this : The 

 stem was clipped oif as near the basals as possible, and then the stump 

 jDared down with a knife as much as could be done without danger 

 of injury to the basals, so as to leave a minimum of work to be done by 

 the caustic, A small cavity was scooped out of the small portion of 

 the stem remaining, and the specimen w^as then dried. The drying is 

 to insure localization of the action of the caustic ; for if the specimen 

 be wet the caustic will rapidly infiltrate through the sutures and 

 articulations, weakening the specimen so that successful manipula- 

 tion is rendered very difficult ; in a dry specimen, on the other hand, 

 the infiltration is comparatively slow, and the action of the caustic 

 may be to some extent gauged by the amount of moistening (and 

 consequent darkening) of the exterior of the specimen. The interior 

 infiltration appears to be more rapid than the spread of the moist 

 area on the e:^terior, so that, by the time the basals are moistened all 

 over, the specimen is ready for dissection. Dissection is accomplished 

 under a dissecting microscope, using a lens of as strong magnification 

 as can be employed without hindering the work by too great a dimi- 

 nution of the working distance and field of vision. The caustic is ap- 

 plied in the form of a small lump, and is allowed to deliquesce, the 

 solution thus formed passing down the central lumen of the remain- 

 ing stem joints and infiltrating out between them. When the disin- 

 tegration is believed to have proceeded far enough, the specimen is 

 soaked in water to remove the caustic, and is then ready for dissec- 

 tion. It will be found that the first few stem joints, being large and 

 thick, are quite difficult of removal, and must be broken up and taken 

 out piecemeal ; but the smaller interior joints are perfectly free. If too 

 great difficulties are encountered, as much should be removed as is pos- 

 sible without danger to the specimen, and the caustic applied again 

 for a short time. There are two dangers to guard against; usually, 

 after dissecting away the rapidly decreasing stem joints, until an ex- 

 ceedingly small one is reached, which is also removed, apparently the 

 entire dorsal surface of the basals is laid bare, showing no trace 

 whatever of infrabasals. This, however, is not the case; the appear- 

 ance is produced by a stem joint nearly full size, and so intimately 

 connected with the basals along the edge that it is practically indis- 

 tinguishable from them. By inserting the point of the needle into the 

 central lumen and carefully prying upward, this joint may be 

 broken away, when another series of small joints will be exposed. 

 The infrabasals are so patent that it is impossible to overlook them ; 



