478 ON CAEBONIFEEOUS ENCRINITES. 



specimen in the British Museum in bad preservation, which looks 

 very much like a wiinkled membranous tube. 



These specimens exhibit the following structure. One of them is 

 4 J inches long by f inch wide. Above the anal plates are two plates 

 side by side, about twice as wide as long, which have two prominent 

 lateral ridges on each side ; these are followed by two shorter plates 

 which have two lateral ridges. These four plates give strength to 

 the base of the proboscis, and are followed by the ordinary plates. 

 The proboscis is formed of long narrow plates, arranged in five 

 horizontal rows, and set at right angles to the axis of the proboscis. 

 The most prominent of these are pairs of plates bearing high ridges, 

 which are pressed against each other so as to form a single strong 

 ridge across the proboscis. Of these there are in one case 43. Each 

 of these pairs is separated by three, and in one case by five plates, 

 of which the central one is the largest, and all of which are rather 

 higher in the centre, so as to form five longitudinal ridges {Plate 

 VI., figs. 1 and 3.) These smaller plates articulate by crenulated 

 edges. 



The interior of the proboscis shows the underside of the three 

 intermediate plates, but instead of the two ridged plates shows only 

 one broader one of which the ends are bifurcated. They thus 

 appear to underlie and hold together the ends of the ridged plates. 

 I have found some broad plates free, which appear to have a 

 deep socket at each end, and which seem to be different from the 

 plates visible on the exterior. It is possible that the bifurcation 

 mentioned may be only a section of these sockets, but further 

 investigation will be required to settle this point. {See plate VII., 

 fig. 2.) Among the detached plates I have found some short ones 

 which are bent at a high angle, and which do not seem to have been 

 subjected to compression. {See plate VII., fig. 2.) It is difficult 

 to assign to these their proper place, unless the proboscis was not 

 circular but oval in section, on one side at least. The position of 

 the proboscis was not central but on the side of the anal plates ; 

 this is evident in nearly all the specimens exhibited. In the 

 interior of the head of one specimen are a number of very small 



