406 History of the Hairy-backed Animalcules. 



ment, the great size of the egg, and its chitinous shell, are 

 decidedly Rotiferous.* A great cerebral ganglion, exactly cor- 

 responding to that of Notommata aurita, N. trijpus, and others, 

 is found in Taphrocampa, and indistinctly in D. antenniger. 

 The inastax, so eminently characteristic of Rotifera, is fully 

 developed in Taphrocampa, where, however, the form and 

 extent of the alimentary canal are as in Ghoetonotus. The 

 furcate posterior extremity is not a tail but a foot, as in Roti- 

 fera, the cloaca opening on its dorsal side ; it is not indeed 

 separately moveable even in Taphrocampa, yet its homology 

 with the foot of Notommata cannot be overlooked ; it is want- 

 ing in Turbanella, Echinodera, and Dasydytes ; so it is in those 

 true Rotifera, Asplanchna and Anurcea. The very long 

 attenuate hairs that radiate from the face in several (perhaps 

 in all) of the Ghostonoti, which have a singular power of indepen- 

 dent vibration, recal the very similar vibratile setse of Floscularia 

 and Stephanoceros ; and possibly the little hooked organs which 

 I find on the front of G. maximus, and the club-shaped horns of 

 D. antenniger, may have a parallel in the frontal hooks of 

 Melicerta. 



In short, if Taphrocampa has a true affinity with Ghoetonotus, 

 there can be no question that the family belongs to the Roti- 

 fera. It is true there are important diversities between these 

 genera, but there are forms which bridge the hiatus. Echino- 

 dera seems to approach closely to Taphrocampa, but Echinodera 

 has much in common with Dasydytes. Turbanella is very 

 peculiar, yet I doubt not Schulze is right in allying it with 

 Ghoetonotus. It is, doubtless, a group whose members mani- 

 fest great diversity ; but probably there remain many forms to 

 be discovered which will further facilitate transition from one 

 to another, and illustrate its exterior relations. 



In the cilia-ring on the head of Turbanella in its curious 

 setiferous lateral processes, in the form of its head, in the annu- 

 lation of Echinodera and Taphrocampa, and in the long hairs of 

 Dasydytes, especially the terminal tufts of D. antenniger,^ there 

 seem to be some strong points of alliance with Annelida, and I 

 urn inclined to place the family on the border-ground between 

 these two great classes, the Rotifera and the Annelida, with 

 a preponderance of characters belonging to the former. 



* The relative position of (lie reproductive and tlio digestive organs is, however, 

 contrary to that which obtains in the Rotifeha ; in which the latter are dorsal 

 the former ventral. 



t I bog to refer, for depcriptions and figures of the young forms of some 

 murine Annelida, to my Tenby, p. 279, und PI, w. 



