ENTEROPNEUSTA GENERA 



proposed to divide the old genus Balanoglossus into four ; but he 

 now recognises no less than nine. 1 Some of the more important 

 characters are given below, but for the arrangement of the 

 muscles, important from a systematic point of view, reference 

 must be made to the original sources. 



A. Xotochord with a vermiform process (Fig. 7, v) ; pericardium with 

 anterior diverticula more or less developed. . GLANDICIPITIDAE 

 (a) Liver-sacs and synapticula present ; gill-slits almost equalling the 



pharynx in depth, so that the ventral, non-branchial part of the 

 pharynx is reduced to a mere groove (Fig. 6) ; nerve-roots absent ; 

 pericardia! diverticula long. . . Schizocardium, Speng. 



(6) Liver-sacs absent ; 2 ventral part of pharynx well developed ; peri- 

 cardial diverticula short. 



(i.) Synapticula and nerve-roots absent. . Glandiceps, Speng. 



(ii.) Synapticula present ; nerve-roots present or absent ; genital 



region with dermal pits. . . Spengelia, Willey. 



B. Notochord with no vermiform process ; pericardium simple ; ventral 

 part of pharynx large, and sometimes more or less separated from the 

 branchial part (Fig. 4). 



(a) Liver-sacs, 3 synapticula and nerve-roots present. . PTYCHODERIDAE 



(i.) Genital wings well developed. 



(a) Gill-sacs opening by long slits. . Ptychodera, Eschsch. 



(J3) Gill-sacs opening by small pores. Balanoglossus, Delle Chiaje 

 (ii.) Genital wings hardly developed. . Glossobalanus, Speng. 



(b) Liver-sacs, synapticula and nerve-roots absent. . HARRIJIAXIIDAE 



(i.) Proboscis long ; one proboscis-pore. . Dolichoglossus, Speng. 

 (ii.) Proboscis short ; two proboscis-pores. 



(a) Two pairs of genital wings. Stereobalanus canadensis, Speng. 



(ft) No genital wings . . . Harrimania, Bitter. 



The name Balanoglossus was introduced by Delle Chiaje in 

 1829 for B. clavigerus (Fig. 1, A), from the neighbourhood of 

 Naples. As Spengel has shown, its etymology has been much 

 misunderstood. The second half of the name refers to a fancied 

 resemblance between the Balanoglossus, with its largely developed 

 genital wings, and the tongue of an ox. /SaXavo? means " acorn," 

 and it has usually been supposed that this name was suggested 

 by the resemblance of the proboscis, projecting from the collar, 

 to an acorn in its cup, a view which finds its expression in the 



1 Zool. Jahrb. Syst. xv. 1902, p. 209. The Harrimaniidae = Balanoglossus of 

 the Monograph (1893): Glossobalanus Ptychodera, s.str., 1893: Balanoglossus = 

 Tauroglossus, 1893: Ptychodera = Chlamydothorax, 1893. 



2 Punnett ("Enteropneusta," in Gardiner's Fauna and Geogr. Maldive and 

 Laccadive Arch. ii. Pt. ii. 1903) finds small liver-sacs in Spengelia, and describes 

 jnilcyia, a new genus of Glandicipitidae. 3 Exc. G. ruficollis, Willey. 



VOL. VII C 



