PHYLLOCH.ETOPTERUS. 129 



of Bojanus having its external opening on the pinna, but he does not specially describe 

 the supposed opening of the segmental organ into the intestine. The author thus 

 introduced considerable confusion into the description. 



A curious observation was made by Verrill 1 (1882), viz. that Ghsetopterus perga- 

 mentaceus at low water, at Nanshon Island, enlarges its tube by making slits in it, then, 

 spreading it out, fills up the " gore or gusset " with fresh secretion. 



Beraneck 3 (1894) describes the larval Ghsetopterus as having its feet developed early, 

 and, with the ciliary crowns, acting as locomotor organs during the prolonged pelagic 

 stage. He thinks the ancestors were probably free, and in becoming sedentary the 

 posterior region has been specially modified. The setigerous processes extend along half 

 the body in the young, but in the adult they occupy only a sixth. 



An interesting account of the green colouring matter of the intestinal wall (middle 

 region) is given by Ray Lankester 3 (1897), in which he shows that it differs from Bonellin, 

 and hence the name Cha3topterin is appropriate. 



Gravier 4 (1904) notes the discovery of a nucal organ in a new Telepsavus in the 

 form of a small process on the surface of the prostomium on each side, between the 

 insertions of the tentacles. These processes resemble the lappets of Autolytus. 



The same author, 5 in his Red Sea Annelids, describes a variety of Chdetopterus vario- 

 pedatus distinguished only by the small number of the segments of the posterior region. 

 In a ripe female he found a curious external appendage in the middle region, with a 

 rounded extremity and a flask-shaped base, which he associated with the segmental 

 organ, being situated immediately above its orifice, and he thinks that it is connected 

 with the issue of the ova. 



Delagia Ghsetopteri, a curious Polyzoan with creeping stolons, was found on the inner 

 surface of the tube of Chdetopterus on the shores of France by Joyeux-Laffuie 6 (1888). 



Genus XCV. — Phylloch^topterus, Grube, 1 1863, Char, emend. 



Cephalic lobe small with a grooved ridge in the mid-dorsal line. Buccal funnel 

 somewhat like that of Chdetopterus variopedatus. Tentacles two pairs, unequal, simple, 

 the shorter with an internal bristle. Eyes two, lateral in position. Body of three regions, 

 the anterior being flattened and with ten pairs of well-marked simple feet furnished with 

 bristles having spear-shaped tips. The fourth is longer than the others, and bears 

 a single, powerful chitinous bristle resembling a molar tooth and beyond it a short row of 

 bristles with flattened hastate tips. Eleventh bristled segment (first of the second or 

 middle region) has two dorsal branchiae, a flattened lobe in the lateral region, and below 



1 Rep. Comm. Fish and Fisheries, U.S.A/ 



'Rev. Suisse Zool./ t. ii, p. 377, 1 plate. 



f Quart. Journ. Micr. Sci./ vol. xl, n.s., p. 447, 4 pis. 



f Comp. Rend. Acad. Sc/ Paris, t. cxxxix, p. 545. 



' Nouv. Archiv. Mus. Paris/ 4 e ser., t. viii, p. 186. 



( Arch. Zool. exper./ 2 e ser., t. vi, p. 115. 



' Archiv f . Naturges./ Bd. xxix, p. 54. 



140 



