118 Mr Thomas A. Huxley on a Hermaphrodite and 



Not only does it appear to me that, under these circum- 

 stances, it is inexpedient to create new sectional terms ; but 

 until a more extended and careful examination of the tubi- 

 colar annelides shall have been made with reference to these 

 very points, I do not think it is worth while even to found a 

 new genus for the form I am about to describe, as it possesses 

 all the essential characters of Protula. Specifically, however, 

 it appears to be distinct from all forms of Protula hitherto 

 described, and I therefore propose to call it Protula Dysteri, 

 after my friend Mr Dyster of Tenby, in whose society it was 

 discovered, and from whom I hope some day to see good work 

 in this branch of science. 



1 have already described the vermidom of this species, and 

 I now therefore pass to the details of the organization of the 

 animal itself. Protula Dysteri (fig. 3) possesses a very elon- 

 gated body, which may be conveniently divided into a cephalic, 

 a thoracic, an abdominal, and a caudal portion. 



The cephalic portion (fig. 3, e) can hardly be said to constitute 

 a distinct head, for the oral aperture, which is wide and funnel- 

 shaped, is terminal. The dorsal margin of the oral aperture 

 is formed by a prominent rounded lobe, beneath which are 

 two richly-ciliated, short filaments, which adhere to the base 

 of the branchial plumes, and might be regarded either as their 

 lowest pinnules, or perhaps, more properly, as tentacles ana- 

 logous to the operculigerous tentacles of the Serpulse. On the 

 ventral side the margin is deeply incised, so that a rounded 

 fissure, bounded by two lips, lies beneath and leads into the 

 oral cavity. From each side of the head springs a distinct 

 branchial plume, whose peduncle immediately divides into four 

 branches. These are beset with a double series of short filiform 

 pinnules, the origins of each series alternating with those of 

 the other. The termination of each branch is somewhat cla- 

 vate, and when expanded the eight branches are usually grace- 

 fully incurved towards one another, the whole having not a 

 little the aspect of a Comatula.* 



The thoracic portion of the body (fig. 3, ef) is short, but 

 wide and somewhat flattened. It is produced laterally into nine 



* It i9 worthy of note, how very crinoid the branchial plumes would be if 

 their skeleton were calcified instead of simply cartilaginous. 



