DESCRIPTIOxN OF GENERA AND SPECIES. 



Order GEPHYREA. 



Auuelids with degenerated segmentation, without external jointing, without para- 

 podia, and without dorsal gills. There is a closed vascular system, and one to three 

 (rarely six) pairs of segmental organs. There are seldom numerous setfe, and in most 

 species none. The sexes are separate. Found in all seas. 



A. Gephyeea ch^tifera. 

 Gephyrea ivith setcB. 



Genus 1. Sternaspi's, Utro. 



The body is indistinctly segmented, and there are bundles of seise both anteriorly 

 and posteriorly. The ventral surface is smooth, and at the posterior end there is a .shield, 

 the borders of which are provided with setaj. The anterior end of the body bears a long 

 forked proboscis. Anus at the posterior end, and lieside it numerous retractile gill- 

 filaments (Kiemenfaden). Found in all seas. 



Since Sluiter found a long forked proboscis in the East Indian Sternaspis spinosa, 

 Sluiter, we are probably justified in assuming the presence of a similar proboscis in the 

 other species of the genus, although it has as yet been observed only in that one. 

 Sluiter himself reports, indeed, that the proboscis is always thro-mi off by the animal a 

 few minutes after its capture. 



It does not seem to be beyond question whether the form preserved in the Challenger 

 collection can be regarded as really the representative of a distinct species. All the 

 species of Sternaspis as yet knovvTi are very like one anothei", and our Sternaspis princeps 

 is only distinguished by subordinate characters, on the one hand from Sternaspis 

 spinosa, Sluiter, from Batavia, and on the other from the Sternaspis costata of Mareu- 

 zeller, from the Bay of Aliya. The imperfect preservation of the Challenger specimen 

 unfortunately does not admit of any intimate description of the anatomical structure. 



