ACANTHOCEPHALA, GEPHYREA. 
Verm. 21 
Notes on other species: Cobbold (2) pp. 202-204; E. transversus^ 
Rud. [Turdus iliacus'}, echinodiscus, Dies. [^Myrmecophaga tamandua] 
and eleganSy Dies (pi. xvi. figs. 1-9) \Uapale cedipus]. 
IX. GEPHYREA. 
1. Kowalewski, a. Du male planariforme de la Bon^lie, traduit du 
Russe par J. D. Catta. Montpellier : 8 pp., 1 pi. 
2. Salensky, W. Ueber die Metamorphose desjEJcAiwrwff. Morphol. JB. 
ii. pp. 319-327, pi. xxii. 
3. Schenk, S. L. Der griine Farbstoff von Bonellia viridis. SB. Ak. 
Wien, 1875, 5 pp. 
4. Th^iel, H. Recherches sur le Phascolion strombi. Sv. Ak. Handl. 
(n. f.) xiv. 2, 32 pp., 2 pis. 
Species: Phascolosoma japonicum. sp. n., Grube, JB. schles. Ges. 1876, 
p. 60 (Z. ges. Naturw. 2, xiii. p. 96), from Japan ; P. tubicola, Verr., 
and boreale, Kef. ?, S. J. Smith & 0. Harger, Tr. Conn. Ac. iii. p. 46. 
Chcetoderma nitidulum, Lov., iid. 1. c. pi. viii. fig. 3. 
Aepidosiphon sp., near A. steensirupiy from St. Vincent ; Grube, 1. c. 
Evolution, Anatomy, &c. 
Evolution. The Echiurus larva is shaped according to the Lov4* 
uian” typo of \ 2 iX\dl Annulata \ during growth, the anterior portion of 
the body is transformed into a trunk (proboscis), whilst the posterior is 
elongated, and develops the anterior paired hooks and the posterior circle 
of booklets, the respiratory sacs, the ganglionated ventral nerve-strings » 
&c. Salensky (2). 
Anatomy. ThiSel (4) describes the anatomy of Phascolion strombi 
(Zool. Rec. xii. p. 542), the spines, tubercles, and papillae of the skin, its 
cuticle, epithelium, and “ follicles.” As to the interpretation of the latter 
as glands (Z. c. p. 641), or sense-organs, he does not pronounce any decided 
opinion, rejecting, however, the nervous nature of the filaments connect- 
ing them with the subjacent muscular stratum in some species. The 
muscular sac is undivided, composed of external circular and internal 
longitudinal fibres, to which are added, between the two layers, separate 
delicate oblique bands. There are two retractors of the intestine, a 
large dorsal and a ventral, both inserted in the hindmost portion of 
the body cavity. The nervous cord is single, without ganglia, ending 
posteriorly in two ramifying branches, giving off lateral branches in its 
course, and continued anteriorly in the ring and brain, encircling the 
parts immediately behind the base of the twenty tentacles. The body- 
cavity is filled with the nutritive fluid, which circulates in a definite 
manner, as observed in young specimens, from before backward along 
the ventral portion of the body, and from behind forward in the dorsal ; 
it contains blood corpuscles of different types, also, at times, ova and 
