28 THE KOTIFERA. 



Genus COPEUS, Gosse. 



[GEN. CH. Usually of large size, ventricose behind the middle, furnished with 

 organs of sense l in the lumbar regions ; brain usually threefold ; body tailed. 



The type of this natural group is, as already observed, Notommata copeus, of Prof. 

 Ehrenberg, which I propose to honour with his own name, Copeus Ehrenbergii. As I 

 have myself found several other species closely allied to this, yet quite distinct, in a very 

 brief period, and in one locality, it is probable that future research may considerably 

 augment their number. 



The feature which peculiarly marks the genus is the existence of organs, doubtless of 

 some unknown sense, not only in the vicinity of the great brain (where their presence 

 is quite normal), but in the lumbar region of the trunk, far from the brain, where it. seems 

 strange to find them, and where the form and conditions of the surrounding parts 

 seem to preclude their advantageous exercise. This, however, is but the expression of 

 our ignorance. 



In many cases there is some extraordinary development of the ciliary system, in the 

 shape of wide expansions of the face, or remarkable forms of the auricles, lately 

 described ; and sometimes the tail takes unusual shape and size. The skin, in several 

 cases, has the power of secreting a dense mucus, insoluble in water, so as to constitute 

 a thick coherent mantle for the animal, in which extraneous matters are entangled ; and 

 the production and retention of this seem to be subject to the animal's will. 



It is perhaps in harmony with this specialty of sense-development that the brain itself 

 is generally of great size, and of complex form ; for there is often, in addition to the central 

 sac, which is sometimes pyriform with a tubular stalk, a secondary sac on each side. 



The species are for the most part of large dimensions, heavy and unwieldy in motion, 

 and vegetable feeders. P.H.G.] 



C. LABIATUS, Gosse, sp. nov. 



(PI. XVI. fig. 1.) 

 Notommata centrum . . . Leydig, Ueb. d. Ban d. litiderlh. p. 33. Taf. iii. fig. 21. 



[SP. CH. Lumbar regions furnished on each side ivith a stout seta (apparently 

 single] projecting horizontally ; tail pointed; chin projected into a long, horizontal, 

 channelled, ciliated process, very versatile ; brain threefold. 



This noble species I at first thought to be the N. copeus of Ehrenberg. Yet the 

 dissimilar structure of the head presently showed that it is quite distinct. 2 There is no 

 trace of the great lateral telegraph-like arms which project from the head in C. Ehren- 

 bergii; what answer to the auricles being small ciliate channels, bent-over at their ends, 

 into which the front is produced on each side. These cilia are continued along the frontal 

 margin : while from the lower part of the face projects horizontally forward a very 

 moveable lip in the form of a great fold of transparent flesh, of which the two sides, 

 sloping outward, make a channel as long as the width of the head, deep at the base, but 

 coming to a point, its edges, which fold over toward the hollow (see fig. la), being fringed 

 with locomotive cilia. From the occiput projects, pointing outward and forward, a stout 

 antenna, of outline swelling to about seven-eighths of its height, then diminishing with 

 an angle, to a truncate end, whence issues a brush of divergent setas, evidently connected 

 by internal nerve-threads with the brain beneath. The ciliation of the face reaches far 

 below the lip on the ventral surface. The longitudinal muscles are very numerous and 

 conspicuous. Immediately behind the front is a row of (at least) four oval translucent 

 masses, which may be compared with the globose masses in the head of Hydatina 



1 An account of these " sense-organs," "antennae," or " tentacles," in the whole Class, will be given 

 at the end of Part VI. C.T.H. 



2 Dr. Leydig, who (loc. cit.) has well described and figured this species, assumes that it is the 

 N. centrura of Ehrenberg. But so practised an observer could not have overlooked the great lip, if 

 labiatus had indeed been before him. 



