298 Miscellaneous. 



present the moniliform aspect so frequent in the Annelida. In this 

 region it is surrounded by a sort of muscular sphincter belonging to 

 the septum ; elsewhere it presents the ordinary longitudinal and 

 transverse muscular coats. Its internal epithelium, of a green 

 colour, is very strongly vibratile throughout its whole extent from 

 the mouth to the anus. The circulatory apparatus is composed of a 

 dorsal vessel bifurcating in front at the level of the vibratile pits, 

 but also emitting a little lower down two oblique branches directed 

 forwards and joining the vertical branches resulting from the bifur- 

 cation. In each ring the dorsal vessel emits a lateral loop ; and all 

 these loops seemed to me to terminate in a median ventral vessel. 

 The vascular apparatus of Polygordius Villoti is therefore more com- 

 plicated than that of its congeners, in which there is no ventral 

 vessel and the lateral loops terminate coecally. 



The genital elements are developed on the walls of the body and 

 of the longitudinal partitions in all the rings behind the first four 

 or five. They are free in the general cavity, where in the males 

 the tails of the spermatozoids may be seen floating and stirring 

 about like a sort of vibratile lining, when the heads are still united 

 in a single group soldered to the walls of the cavity. The heads of 

 the spermatozoids are pointed at the pole opposite the tail ; they 

 afterwards swell out into a sphere, and then enlarge a little, so as 

 to form a sort of disk, from the centre of which springs the tail. 

 Spermatozoids of this form have been figured in some Annelides. 

 The ova have a vitellus of an orange colour, and often several 

 germinal spots ; they cause the female to be of a more decidedly 

 reddish colour than the male. The evacuation of the products 

 of generation is effected by the intermediation of segmentary 

 organs, which are but little folded upon themselves, and vibratile 

 throughout their length. 



By these various characters Polygordius Villoti. as may be seen, 

 approaches very near to the Annelida ; but the absence of locomotive 

 setse, and the presence of vibratile pits on each side of the head, 

 would tend to approximate it to the Nemertians, from which, how- 

 ever, it is excluded by the absence of vibratile cilia on the integu- 

 ment and the distinctness of the septation. I see no character 

 which justifies at all clearly the approximation of Polygordius 

 Villoti to the Nematodes. 



I propose to resume shortly the researches which I have commenced 

 on this interesting type ; their results will appear in the 'Archives de 

 Zoologie experimentale ' of Professor de Lacaze-Duthiers. — Comptes 

 Ilendus, April 26, 1875, p. 1101. 



On the Development of the Spinules in theScales of Gobius mger(Linn.). 

 By M. L. Vaillant. 



The theories admitted by anatomists with regard to the origin of 

 the spinules may be divided into two principal ones : either these 

 processes result from simple notchings of the posterior margin of 

 the scale, and being calcified with the lamella are only a dependence 



