The Trixoids from Dr. S. Bock's Kxpeditiox to Japax 1!H4. S'.> 



lia\e the most ai'iiis. l)ut latlicr the i'ever.so. It is pi-ohaljle. as I hav^e 

 suggested when Ireathig the above-mentioned s|)ecies, that tiie question 

 of catching the food plays a certain rcMe. but possibly (Ihougii not very 

 likely, cosidering that 1 have often seen »(hi])licative» regenerates 

 situated on Br 1, but never a single arm regenerated from the same 

 ossicle) one might also connect the phenomenon with the fact that the 

 family Colobometrichr strongly tends to a X-ai-med type and that this 

 is reached only after a transition stage with more than X arms. 



By the small trans\'ei'se cai'inatioii (on some segments replaced 

 by a pair of microscopic (ul)ercles) on the proximal eirrals the new 

 species pro\es itself to be a form of an Oligophreat type, though other- 

 Avise it presents much that reminds us of certain Peromeirinfi (the rela- 

 tively large size of tlie centrodorsal cavity and the j)osition of the 

 rosette, which only radially forms »spout-like» processes). 



The new species approaclies most to C. manca, from which it 

 <liffers by a smaller and less discoidal Cd. by longer eirrals, which 

 have only inconspicuous cai-inafions, by the absence of III Bi" — s, 

 by the short interval between the syzygies, and by Pg being ahnost 

 smooth. 



The species is an interesting form, showing a strong tendency 

 of con\'ergence towards the Macrophreat tyj)e. 



■68. 69 Cyllometra diseifnrmix (St. iio) 68) Ann-sturnp with a genital iiiiinule ",i. 69) Cirrus " i; 70,71 

 Trnpiometra eucrinns (St. 4.")), 70) Cirrus '/i. 71) Distal pinnule °i; 72, 78 Pecfinonii-tra Jtavnpur- 

 pHvra 72) P, ", i . 73) Distal pinnule (i — 5 pairs of Sacculi per segment) '*/i; 74) Cenometrn hella 

 Cirrus "i; 75. 76 yrnmelra iititlticiilor (St. 1'2). 75 a) DistaV pinnule (the tip broken) "i, b) The 

 tiji of the pinnulf from another specimen (in Dr Mortknsen's collection) '■* i, 76) P, '* i: 77. 78 Crosso- 

 mitrn septentriniialis (St. 36), 77) Pn (the 7 last segments broken) ''', i , 78) Distal pinnule '* i; 79 — 83 

 Diodonfometrn Bncki (St. 56) 79 a) The penultimate segment viewed from the proximal end. b) The 

 same segment viewed from the distal end. X 17 ' ■;. 80) P, " i. 81) Cd with tlie cirri arranged in 

 radial groups (observe tlie distal face of I I'.r 1) '■', i . 82) (ienital pinnule '■" i, 83) Distal pinnule '*,i. 



Nova Acta Reg. Soc. Sc. Ups.. Ser. 1. Vol. 5. N:o 6. Impr 



