1882.] CLASSIFICATION OF THE COMATUL^. 733 



The following are cases in which Prof. Bell has wrongly applied 

 his own method : — 



1. Antedon maeronema. According to Bell's formula (3 A—) 



this species only differs from the ten-armed -4n/. rosacea (SA^) 

 in the cirri consisting of more than 40, instead of less than 20 joints. 

 And yet Miiller' says, " Ans den 5 Armstiimmen von 3 Radial- 

 gliedern entwickeln sich meist 3 Arme, so dass sich ein Stamm zuerst 

 in einen dicken und diinnen theilt, der dickere aber ilber dem zweiten 

 Glied oder brachiale axillare sich wieder in 2 Arme theilt." The 

 " brachiale axillare^' is what we now call the " distichal axillary ;" 

 and as it does not " present a syzygial joint," Prof. Bell's formula 



should be V3A- 



e ■ 



2. Antedon palmata. The same formula is given for this species 

 ^3 Ar) as for Ant. carinata, which has ten undivided arms. In 

 Ant. palmata'-, however, " Die 10 Primararme bestehen aus 2 

 Ghedern, das zweite axillar. Nach der Theilung wieder 2 Glieder, 

 das zweite axillar. Entweder bleibt es dabei oder die Arme theilen 

 sich wieder." That is to say, there are two distichals and two 

 palmars, and sometimes even a further division, none of the axillaries 



being syzygies. Hence the formula should be V3 A^ ; but this is 

 insufficient, as it gives no information about the presence of any 

 axillaries beyond the distichal one. 



Both the errors above noticed are due to the omission of the sign 

 V , and are possibly due to the printer. But others are of a much 

 more serious character and require to be treated in more detail. 



3. Act. alternans. For SA'RPP"? read 3 A'DP'(P"')°- 



4. Act. bennetti. For SA'RDP^ read 3A'DPP'(P")^- 



5. Act.japonica. For \/3A'R^ read SA'DP^- 



6. Act. tnultiradiata. For 2A'RDPg read 2A'DP(P')J' 



7. Act. novce-guinect. For 1(2)A'RDP^ read 1(2)A'RDPP'(P")|. 



8. Act.parvicirra. For 3A'DP'^ read 3A'D(P)*^. 



9. Act.peroni. For 3A'RDPj read 3 A'DP(P')g- 



10. Act pulchella. For (1.2)3A'? read v/1.2.A'?, and 3Af*- 



11. Act. schlegeli. For 3A'RDP- read 3A'DPP'P"-- 



12. Act. iypica. For lA'RD?read 1A'RD{PP'-Pv|°. 



The presence of R or D in a formula indicates that the radial or 

 distichal axillary " is a syzygy ;" and this leads to confusion, for the 

 two cases are not homologous. The radial axillary is never a syzygy 

 in the sense that the distichal axillary is, or that the third or any 

 following brachial may be ; i. e. it never primitively consists of two 



1 hoc. cit. p. 2.')8. = Gattung Comattda. p. 261. 



