HEMICHORDA. 
Verm. 45 
272. [Masterman, A. T.] (2) On the “ Notochord ” of Cephalodiscus. 
Zool. Anz. xx, pp. 443-450. 
273. *Schultz, E. Obrazovanie mezodermui u Phoronis. [On the formation 
of the mesoderm in Phoronis.'] Trudui St Petersb. Protok., 1897, pp. 
31-34, 3 figg. German Resume, pp. 47-50. Abstract Zool. CB. iv, 
pp. 781 & 782. 
274. Spengel, J. W. Bemerkungen zu A. T. Masterman’s Aufsatz “On 
the ‘notochord’ of Cephalodiscus ” in No. 545 des Zoologischen 
Anzeigers. Zool. Anz. xx, pp. 505 & 506. 
275. Willey, A. (1) On Ptychodera Jlava, Eschscholtz. Quart. J. Micr. 
Soc. xl, pp. 165-184, pi. v. 
276. . (2) Spengelia ; a new Genus of Enteropneusta. T. c. pp. 623- 
630, pi. xlvii. 
277. . (3) Some zoological Results of a voyage to Melanesia during 
the years 1894-1897. P. Cambridge Soc. ix, pp. 397-400. 
BIOLOGY. 
Macbride discusses the relationship of Balanoglossus and Amphioxus , 
criticising LwofF’s description of the development of coelom and mesoderm 
in Amphioxus. Schultz discusses the relationship of the Enteropneusta as 
a whole to the Ectoproctous Bryozoa, coming to no very definite conclusion. 
He describes the formation of the mesoderm in a species of Phoronis 
occurring near Sebastopol. It is apparently formed by the arrangement 
of mesenchyme cells into an epithelium, and would therefore have a 
different origin to what it has in the species whose development has been 
described by Caldwell. Schultz does not give the name of his species. 
The anatomy of Cephalodiscus is fully described by Masterman (1), and 
compared with that of the Actinotrocha- larva of Phoronis. 
The homology of the “ notochord ” of Cephalodiscus with the “ proboscis 
gland” of Balanoglossus and “subneural gland” of Actinotrocha , maintained 
by Masterman, is disputed by Harmer, who still regards it as homologous 
with the “ Eicheldarm ” of Balanoglossus. Masterman (2) upholds his own 
views and criticises some of the figures in Spengel’s monograph. Spengel 
objects to these criticisms. 
The relationships of the different genera of Enteropneusta to one another 
are discussed by Willey (1, 2 & 3). He concludes, in opposition to 
Spengel, that the genus Ptychodera , with an outer layer of circular 
muscles and synapticuloo, is the most primitive, then follow Schizo- 
cardium and Glandiceps , with an inner layer of circular muscles and no 
synapticulse, Balanoglossus , characterised by the absence of circular 
muscles and of synapticulse, being the least primitive. He describes a 
new genus, Spengelia , resembling Glandiceps , but approaching Ptychodera 
in the possession of synapticulse and of the remains of dorsal-roots 
arising from the collar nerve-cord, and especially characterised by a 
well-defined layer of splanchnic nerve-fibres round the buccal cavity and 
oesophagus, and by the occurrence on each side of the dorsal median line 
of a series of deep dermal pits in the post-branchial region of the body. 
He proposes (2) the term “ proboscis- coecum ” for the process extending 
forwards from the anterior end of the notochord in Glandiceps and 
Schizocardium (“ Eicheldarm” auct.). 
Hill (Pt. ii) describes a new species of Ptychodera without circular 
muscles in the trunk and having its genital-pleura? rudimentary, with the 
dorsal diverticula of the intestine glandular, with the two longitudinal 
1897. [Vol. xxxiv.] e 31 
