XO. 1820 RECENT CRINOIDS FROM PHILIPPINES — CLARK 20/ 



COMANTHUS CUMINGII (J. Muller) 



Station No. 5137; off Jolo town; 20 fathoms. 



Station No. 5142; north of Jolo town; 21 fathoms. 



This very distinct species has about ten cirri with thirteen joints. 

 It is hardly necessary to call attention to the fact that none of Pro- 

 fessor Bell's records of "Actinometra cumingii" refer to this form. 



COMATELLA new genus 



The type of arm structure found in "Actinometra^' pulchella (i. e., 

 alata) , macttlata, stelligera, and nigra differs from that found in 

 any other group. The division series are all 2, but the first two 

 brachials of the free arm are united by syzygy. In ten-armed speci- 

 mens belonging to one of these species, or in arms springing direct 

 from the costal in others, the first syzygy is between the third and 

 fourth brachials. Assuming the t3^pe of arm division to be extra- 

 neous, and Z^ and Z„ to be the distichals, this would be at once ex- 

 plained ; for a splitting of the arm just before the first syzygial pair 

 would, of course, result in a doubling of the syzygial pair, these two 

 resultants resting upon Z., as an axillary ; thus we would get dis- 

 tichals 2, and a syzygy between the first two brachials. This is the 

 condition found in maculata and in the majority of specimens of 

 alata; but in some specimens of the latter, and in stelligera and 

 nigra, from one to five additional axillaries occur. Now the man- 

 ner of occurrence of these additional division series is unique ; in 

 nigra, starting from the distichal axillary, they are only found ex- 

 teriorly, so that from each distichal axillary there spring two main 

 tritnks giving off interiorly at every two joints an undivided arm, 

 after the last axillary ending in undivided arms themselves. In 

 stelligera and in alata, when palmars are developed, the costal ax- 

 illary instead of the distichal is the starting point. The first two 

 joints of the undivided arms and of the terminal arms at the end of 

 the branching trunks always have a syzygy between the first two 

 brachials ; but in alata and in stelligera, in arms springing from the 

 costal axillary the first syzygy is between the third and fourth brach- 

 ials. The natural inference is an extraneous division, as in Comas- 

 ter, but just before, instead of just after, the first syzygial pair. 

 When exterior palmar series are developed in alata and in stelligera, 

 we get a peculiar state of affairs ; for internally the distichals repre- 

 sent the first two brachials of a free arm followed by the third and 

 fourth (a syzygial pair) as usual ; but externally they represent an 



