The Crinoids from Dr. S. Bock's Expedition to Japan 1014. (i;{ 



2) 'I'he highei- di\ision-series, which are an iin|Hiriaiit charae- 

 terislie of classiHcaticm. have not yet appeared. 



3) The proximal ossicles of the arm become longer compared 

 with the breadth, the younger the animal is. This is also applicable 

 io a still greater extent to the distal Br-segments. The distal ends of 

 the Br-segments are serrate and bent outwards. 



4) The comb on the proximal ])innules, a very reliable charac- 

 teristic in adolescent and full-grown specimens, tends at an early 

 stage to a uniform type and therefore all small young forms have 

 combs with a few, high, rather large teeth. The young forms of the 

 Cnmnster-genus only have combs on the proximal pinnules. 



5) In the very earliest stages the disk has a central mouth and 

 a marginal anal tube. 



As a general rule one can say that young ('omasterids which 

 have a pinnule-gap on the proximal arm-parts (here of course exclud- 

 ing (^omasterids of the Cnmalilia ty])ej are impossible to determine 

 even with tolerable certainty. 



The comparison between the appearance of the disk shows, 

 however, that here j>erhaps, one might get cei'tain fixed points for the 

 judgement of the systematical position of the animal. 



The young of the species of Oomaiella and large Goniissia have 

 a central or subcentral mouth and a short, narrow, inconspicuous 

 anal tube. The skin is tightly stretched on tlie ventral side between 

 the ai-ms so that the disk gets a characteristically lean appearance. 



The young forms of Gomùsia ignota minuta are also in the early 

 stages recognized by having the ambulacral furrows surrounded with 

 cushion-shaped slopes, probably marking the extension of tlie gonads 

 on the disk, and this condition together with (lie characteristic proxi- 

 mal Br-ossicles (ah'tady at an early stage very short), the coarse pin- 

 nule-bases, soon thiclcened by the genital glands, and the smooth proxi- 

 mal arm-parts make them fairly easy to distinguish from young forms 

 of other species in the collection. 



The young forms of Goriiaster and Comantheria in the early 

 stages also have a »fat» (swollen) disk. The anal tube is large, thick 

 and coarse, a little swollen, often (especially in Gomaster delicata gran- 

 dis) strongly papillated or plated. In Gomaster — species the length- 

 growth of the anal tube soon ceases, and in larger indi\iduals the tube 



