ON THYSANOSTOMA BENSCRISPUM, NOV. SPEC. ]_35 



The limb of the cross shapad cent ral stomach is long, narrow and 

 bent downwards (figs. *2, 8). Of the radial canals the four perradial and 

 the four interradial canals alone are prominent. Between each two of 

 these eight canals, we find five or six canals ; but they anastomose with 

 each other and with the eight canals and form a network of irregural and 

 polygonal meshes over the whole surface of the subumbrella (fig. 2). 

 The mesh of the netwok is lai-ge near the points of origin of the perradial 

 and the interradial canals. Outside the circular canal it becomes sud- 

 denly small. 



From each end of the limb of the central stomach, a strong and 

 broad canal runs down through the oral pillar. It is the pillar canal. 

 Each pillar canal is divided into 4 ('2 vertical and 2 horizontal) at the 

 corner of the oral disc (fig. 6). The vertical branches are larger. They 

 go down to the oral arms and form the brachial canals. The smaller, 

 horizontal branches reunite into a short perradial canal which meets 

 with the three other associate canals at the centre of the oral disc and 

 forms the crucial canal for the oral cross. There is no central branch of 

 the pillar canal which is found in Mastlgias physopliora * and PliyUoliza 

 punctata, t 



The canal system of the oral arm is as complex as the suctorial 

 frills ; but each brachial canal is divided into 4 principal canals, 1 central, 

 1 axial and 2 abaxial. The latter three give off many small branches 

 which unite vertically with each other at many places and form many 

 small vertical canals of some length. The 4 canals are united for some 

 distance at the proximal part of the lower arm. The central canal is 

 branched only at the distal end. These may be understood by examining 

 cross sections of an oral arm shown in figs. 7-13. 



The genital glands are broad and much-folded bands which looked 

 according to Prof. Ijima's statement, hazel brown in color through the 

 umbrella. 



* K. Kishiuonye-Descriptioa of a new Rhizosfcoma. This magazine, vol. VII. No. 78. 

 t E. V. Lendenfeld loc. cit. 



