14 OPHELIA LIMACINA. 



Savigny and his Ophelia mamillata would appear to present few differences — other than 

 the more numerous rings of the segments and a few more anal papilla in the former. 

 In his ' Annulata Danica Conspectus ' x 0. mamillata is also entered. 



H. Rathke 2 (1843) found in this species a pore between the dorsal and ventral 

 setigerous processes through which he thought the ova escaped from the body-cavity. A 

 second and larger opening in proximity, was considered to be that of his blind sac 

 (segmental organ). He thought that the cirri were branchial organs. 



Dr. Johnston (1865) included this species under his second division — Limivora, 

 family Opheliacese, and genus Ammo try pane. His descriptions and figures are good. 



De Quatrefages (1865) appeared to be uncertain about the position of this form, 

 which he placed at the end of the Opheliidse. 



Cosmovici 3 (1880) describes in Ophelia radiata the separation of the five pairs of 

 segmental organs from his five pairs of organs of Bojanus, which are anterior, as quite 

 complete, but his figure shows that the anterior organs (his organs of Bojanus) occupy 

 the same relative positions as the posterior and probably represent less developed 

 structures, and they have both internal and external apertures. The five pairs of 

 segmental organs with which are associated the reproductive organs — male or female — 

 follow, and have the same flask-shaped outline and, he says, serve for the transmission of 

 the sexual products. This author observed the deposition of the ova, the animals first 

 enveloping themselves in a glairy mucus in which the eggs are placed, and from which the 

 annelid by-and-by withdraws, leaving a rounded mass with a long tubular process. 

 The eggs are probably fertilised during deposition, and he watched the development. 

 After extrusion from the egg the young Ophelias present an elongated and somewhat 

 spindled-shaped form with two eyes, and groups often attach themselves in a radiate 

 manner to mucus or debris by the tail, and further, by-and-by, secrete a transparent 

 capsule of mucus. During development two caudal papillse appear, and the body at this 

 stage has more than a dozen segments with a conical snout, alimentary apparatus, and 

 anus. 



Kiikenthal 4 (1887) figures in Ophelia limacina a structure in a corresponding position 

 to the sense-organ in Scalibregma, and Eathke 5 described small apertures similarly 

 situated in the same species. They probably are sense-organs, though Rathke thought 

 them ovipores. 



Aw^erinzew (1908) describes a parasitic Infusorian somewhat like an Opalina and 

 which he terms Butschliella ophelise in the intestine of this species from Barent's Sea. 



1 p. 45. 



2 •' Fauna Norweg./ p. 208, Tab. xi, fig. 14. 



3 f Org. Segment. Annel./ p. 62. 



4 ' Jenaiscbe Zeitschr./ Bd. xx, p. 510, Taf. xxiii, fig. 94. 



5 < Beitrage/ Taf. x, fig. 15, p. 203, and Taf. xi, fig. 14. 



6 ' Zeitschr. f. wiss. Zool./ Bd. xc, p. 334, Taf. xix. 



