242 CIRRATULTTS TENTACITLATUS. 



deposits eggs, more or less agglomerated in its tubes, in the interior of Lithothamnion. 

 The wall of the digestive tube is atrophied, but to a less extent than in A, and the animal 

 takes food. 



In their form B, which is ripe in August, the males and females occur in equal numbers 

 and the large yellowish eggs (200//), are shed externally and fertilised in the water. This 

 form gradually undergoes a change into the epitokous condition, with two large eyes, long* 

 bristles, and a more translucent body, the stout, spoon-like crotchets disappear, and there 

 is atrophy of the palps. In the early stage of B only the anterior pair of nephridia are 

 conspicuous, for the authors did not recognise them in the posterior region. Then ensues a 

 series of internal changes, the increase in the size of the eyes, the atrophy of the palps, the 

 shrinking of the branchiae, and the atrophy of the alimentary canal. The animal consumes 

 the reserves accumulated in the eosinophile granulations of the coelomic cells, and develops 

 nephridia in the posterior segments. A gregarine (Gonospora longissima) occurs in the 

 coelom.- 



Caullery and Mesnil consider Heterocirrus ater, De Quatrefages, as identical with 

 Dodecaceria concharum, and so with H. saxicola, Grube, H. fimbriatus, Verrill, and Terebella 

 ostrede, Daly ell. In the case of Heterocirrus viridis it is otherwise. 



Michel (1898) has observed small buds in this genus posteriorly. 



Picton 1 (1879) is of opinion that the brown granules of the heart-body in the 

 Cirratulidse are neither chitin nor guanin, thus differing from the Chloragogens described 

 by Schseppi in Ophelia ; that the ovoid crumpled bodies are chitinous, that fat is present, 

 that iron occurs in the granules, and that glycogen is absent. 



Anna Dyrssen 2 (1912) studied Girratulus cirratus, Audouinia fill g era, and Amphitrite 

 rubra, and considers that the heart is mesodermic, and that the hsemocytes are immigrant 

 coelomocytes ; that the vessels, like the visceral blood-sinus, have an internal connective- 

 tissue membrane ; that there is no vaso-epithelium ; that the walls of the vessels are meso- 

 dermic. But embryological evidence is needed for confirmation. 



Ripe specimens of Girratulus occur in May, and a young example, 3 mm., was 

 captured in September. 



Cirratulids generally frequent sandy mud, often of a putrid nature, though some, as 

 Dodecaceria and Heterocirrus, bore in calcareous substances. Ghsetozone, again, is found at 

 great depths, e. g. 1 250 fathoms in the ' Challenger.' Though some have no proper tube 

 they are truly sedentary forms. 



Genus CVI. — Cirratulus, Lamarclc. 

 Lumbricus, 0. P. Muller. 



1. Cirratulus tentaculatus, Montagu, 1808. Plate XCI, fig. 1; Plate XCII, fig. 1 — tail, 

 from life ; Plate XCVIII, fig. 18— tail ; Plate CVII, figs. 1 and 1 a— bristle and hook. 



Specific Characters. — Head conical, on each side a short distance from the tip an 

 oblique depression sloping outward and backward, and from the union of the converging 

 1 l Quart. Journ. Micr. Sc./ vol. xli, N.S., p. 271, pis. 19 and 20. 

 3 < Jen. Zeitschr. Naturw./ 4B (1912), pp. 365—397, 4 pis. and 5 figs. 



