STUDIES ON POLTCHAT LARVA. 625 
has yet seen the larve before this has occurred) that it is 
impossible to discuss them further. They possess, however, 
and retain until long after the disappearance of the cilia, pro- 
visional sete of exactly the same type as those found in larvee 
of the Spionide and Polydoride. 
The remarkable larve of the Cheetopteridie, which do not 
bear provisional sete, and which differ from all other known 
Polycheet larvee in being mesotrochal, have been fully dis- 
cussed above. 
List or LITERATURE REFERRED TO ABOVE. 
1865. Claparéde, E.— Beobachtungen iiber Anat. und Entwick..,’ 
Leipzig, 1865. 
1867. Agassiz, A.—‘* Young Stages of a Few Annelids,” ‘Ann. and 
Mag. Nat. Hist.’ (3), xix, 1867, pp. 203-218 and 242-254, pls. v, 
vi (reprinted from ‘ Ann. Lye. Nat. Hist. New York,’ viii, 1866). 
1868. Claparéde, E.—‘ Annélides Chétopodes du Golfe de Naples,’ 
Geneve, 1568. 
1869. Claparéde and Mecznikow.—‘ Beitriige zur. Kenntniss der Poly- 
chiten,” ‘Zeitschr. wiss. Zool.,’ xix, 1869, pp. 163-205, pls. xii-xvi. 
1879. Langerhans, P.—‘* Wurmfauna von Madeira,” Pt. I, ‘ Zeitschr. 
wiss. Zool.,’ xxxii, 1879, pp. 513-592, pls. xxxi—xxxiii. 
1882. Wilson, E. B—‘ Early Stages of some Polychxetous Annelids,” 
‘Stud. Biol. Lab. Johns Hopk. Univ. Baltimore,’ ii, 1881-3, 
pp. 271-299, pls. xx—xxiii. 
1885. Fewkes, J. W.—‘ Development of Certain Worm Larve,” ‘ Bull. 
Mus. Comp. Zool. Harvard Coll. Camb. Mass.,’ xi, 1883-5, 
pp. 167-208, pls. i-viii. 
1886. De Saint-Joseph.—* Annélides Polychétes des Cotes de Dinard,” 
Pt. I, ‘Ann. Sci. Nat. Zool.’ (7), i, 1886, pp. 127-270, pls. viii—xii. 
1887. Cunningham and Ramage.—* Polychxta Sedentaria of the Firth 
of Forth,” ‘Trans. Roy. Soc. Ed., xxxiii, 1885-8, pp. 635-684, 
pls. xxxvi-xlvii. 
1891. Andrews, E. A.—‘* A Commensal Annelid,” ‘Amer. Nat.,’ xxv, 
1891, pp. 25-35, pls. 1, ii. 
—— Malaquin, A—* Etude comparée du dévelopment et de la 
Morphologie des Parapodes chez les Syllidiens,” ‘C.R. Acad. 
Sci. Paris,’ exiii, 1891, pp. 43-48. 
