80 T. GiKLEX, 



Finally a few words about the relation between the genera Cn- 

 matella and Comissia. When A. H. Clark in 1909 pi-oposed these two 

 genera he characterized the first-mentioned one (Smiths. Misc. Coil. 

 Vol. 52 p. 207) thus, that species belonging to this genus should have 

 the first syzygy between Br 3 and 4 in arms situated on I Bi-ax, but 

 the first syzygy between Br 1 and 2 in arms coming h'om axillaries of 

 higher numbers. According to Clark's view some arms should there- 

 fore be divided by »extraneous» some others by »intraneous division* 

 and thus one might in this genus have crinoids with so-called »com- 

 pound arms». In the later proposed species GomateUa decora Clark 

 has found a syzygy between Br 2 + 3 (ir on the outer side of the arm- 

 divisions between Br 3 -f- 4. Comalella brachydrra mihi usually, but far 

 from always, has Br 1 -f 2 on the innei- side, 3 -f 4 on the outer side of 

 the arm-divisions. The specimens of C. maculata and G. stclligera that I 

 have investigated usually have Br 1 — 2 3+4, in the case both of the 

 inner and outei- side of the division-series: in a few cases, however, 

 we find Br I + 2. — Most often, therefore, the »compound>> nature of 

 the arms is visible, but by no means always. From what is mentioned 

 above it is evident that the compound nature never appears in X- 

 armed young Gomatellas. How are tiien the latter to be distinguished 

 from the genus Gomissia, the species of which always have X arms? 

 As to this A. H. Clark in the Siboga Fxp. \'ol. 42 B, p. 23 has re- 

 marked that the young of Gomissia can be distinguished from the X- 

 armed young of other genera by very short and broad 1 Br-sei-ies. the 

 ossicles of which are said to be united in very close articulation. As 1 

 have tried to show in describing Gomissia ignota minuta tiiis only iiolds 

 good in full-grown specimens of the species. The small young of large 

 Comissia-species might therefore have rather long I Br-segments and 

 are consequently similar to young Comalellas. Just as tiie inunanent 

 tendency to »compound arm-division» did not appear in X-armed young 

 Gomatellas it cannot, if it exists, assert itself in Co»/iss/«-species \\ Inch 

 never reach beyond the X-armed stage. In i-eality. therefore, the dif- 

 ference between the genera turns out to be a difference between a 

 group of X-armed and a series of nuiltibrachiate forms of Gapillas/crimf. 

 Joint characteristics by which both the genera are distinguished from 

 other genera within the subfamily are as follows: l\ on Br 2, short 

 Br-segments, complete pinnulation, cii-ri of normal comasterid type, at 



