'210 ACTINOMliTRA SCHLKGELH. 



Remarks. The specimen described above is a somewhat 

 mutilated one belonging to a type which is entirely differ- 

 ent from any hitherto described, and at the same time 

 rather rare. I only know of two other species which 

 present the same curious alternation in the number of 

 joints in the successive arm-divisions. 



It is also interesting as showing a stage in the meta- 

 morphosis of the centrodorsal which is less advanced than 

 that exhibited by Actinometra typica. As in that type the 

 ends of the basal rays are visible externally. The nearest 

 ally of this species is one discovered by Prof. Semper at 

 Paudan near Bohol in the Philippine Islands. It has a 

 thin stellate centrodorsal with traces of cirrhus-sockets still 

 visible , but the joints of the arms and pinnules are quite 

 smooth , and there is no sudden increase in the width 

 of the pinnule joints on the lower parts of the arms , while 

 all the lower pinnules are stouter and more fleshy than in 

 Act. alternans. 



18. Actinoinett*tt Svhiegetii , n. sp. 



Description of an individual. 



Centrodorsal a thin circular disc , hollowed in the cen- 

 tre and bearing about 20 marginal cirrhus-sockets. Cirrhi" 

 lost. First radials almost entirely concealed except for their 

 angles which are rounded , thickened and turned upwards 

 so as to rise somewhat above the level of the rest of the 

 calyx ^). Their distal edges are incurved to receive the 

 convex proximal edges of the trapezoidal second radials 

 which are closely united laterally. Axillaries short, barely 

 half as long again as the second radials, widely triangu- 

 lar and in contact laterally. More than 80 arms , the rays 

 dividing five times; each division of three joints the axill- 

 ary with a syzygy. Rays and their subdivisions somewhat 

 closely united by plated perisome as far as the palmar 



1) Tlie inuiith is supposed to bu dowiivvarils and I he dorsal surlaoc ujiwards. 

 Notes tVoixi the Leyden Museum , Vol. Ill 



