256 BISPIRA VOLUTACORNIS. 
In transverse sections of the anterior region the structure of the brain is well shown 
in this form, with the great commissure over the cesophagus, Fig. 151. Moreover, the changes 
in the great cords and the neural canals are illustrated in Fig. 152 for the anterior, and Fig. 
153 for the posterior region. Further, the origin of the skeletogenous elements which pass 
to the branchial filaments, the great vessels going to the system, and the arrangement of the 
grooves leading to the mouth, are demonstrated in Fig. 154. 
NU-G. 
Fre. 153.—Transverse section of the great nerve-trunks in the posterior region. 
ne., nerve-trunk ; n.c., 
neural canal. x Zeiss oc. 4, obj. A. 
Ke ( 
S 
S 
‘yy 
i Lig. 
Po GO 
Fig. 154.—Transverse section through Bispira volutacornis at the base of the branchie. b7.v., branchial 
blood-sinus ; ¢., lobes of collar ; ch., chordoid skeleton ; n., nerve. x Zeiss oc. 4, obj. A. 
SYNONYMS. 
1804. Amphitrite volutacornis, Montagu. Linn. Trans., vu, p. 80, Tab. vu, fig. 10. 
1807. fs rp Turton. Brit. Fauna, vol. i, p. 186. 
1808. 55 % Montagu. MS. vol. Linn. Soc., pl. xi, fig. 1. 
1812. - 55 Pennant. Brit. Zool., iv, p. 89. 
1816. Sabella * Leach. Encycel. Brit., Suppl., p. 452, pl. xxvi, fig. 7. 
1818. Amphitrite ‘ Lamarck. Anim. s. Vert., t. v, p. 367. 
1820. Sabella 53 Savigny. Syst. Annel., p. 81. 
1826, 2? Amphitrite Josephina, Risso. Hist. Nat. Europe mérid., t. iv, p. 410. 
1828. 55 volutzxformis, De Blainville. Dict. Sc. nat., t. lvi, p. 434, 
a ¥ volutacornis, Stark, Hlements, i, p. 155. 
1843. Sabella » Rathke. Nova Acta Cur., Bd. xx, p. 223, Tab. xii, figs, 1—4, 
1843-53. Amphitrite volutacornis, Chenu. Illust. Conch., 11° livr., pl. vi, fig. 3. 
1845. 53 a idem. Bibl. Conch., t. 1°, p. 38, pl. xii, fig. 10. 
ys Rs Johnston. Ann. Nat. Hist., xvi, p. 449. 
1846. Sabella Josephine, Grube. Arch. f. Naturges., p. 53, pl. 11, fig. 6. 
1851. ie s and volutacormis, idem. Fam. Annel., pp. 89 and 140, 
