108 
SYSTEM OF NATURE. 
mollusks, echinodermes and Crustacea, and the connexion 
between or among them seems much less perfect than it 
would have been had the position of the mollusks and 
annelides been reversed, and the echinodermes thus 
brought more immediately into contact with the latter, as 
pointed out by many naturalists, by means of the genus 
Fistularia. But I am not yet aware that the structural 
resemblance of the Holothuridae to the annelides is really 
greater than to the mollusks. Giving the group the wider 
range allowed it under the appellation Nematoneura (of 
Owen), the Epizoa, especially the species of Lemaea, ap¬ 
proach the edentate Crustacea ; the Holothuridae approach 
the mollusks and annelides ; and Comatula, in its adoles¬ 
cent state described as a Pentacrinus, equally approaches 
the Zoophytes. 
