14 THE VOYAGE OF H.M.S. CHALLENGER, 



The two retractors of the proboscis spring from about the middle of the body ; after 

 a short course they run together. The looped intestine has seventy coils or more, and 

 is free posteriorly. In front, attached to the oesophagus, there is a long fixing muscle. 

 There is also a spindle-shaped muscle. There are two segmental organs, entirely free, and 

 opening beside the anus. Hooks are absent. Round about the mouth there is a circle of 

 finger-like tentacles, heart-shaped in cross section. There is a simple contractile tube. 

 The body-wall is rather thin but elastic. 



In the Challenger collection there are two well-preserved specimens from the Pacific, 

 and another single specimen from the east coast of North America. In S2)ite of this 

 very wide diflerence in distribution, a close comparison revealed no structural difi'erence 

 worth recording. 



Habitat.— (a) Station 241, June 23, 1875 ; lat. 35° 41' N., long. 157° 42'- E.; depth, 

 2300 fathoms ; bottom temperature, 35°"1 ; red clay ; trawled (two 

 specimens). 

 (b) Station 44, May 2, 1873; lat. 37° 25' N., long. 71° 40' W.; depth, 

 1700 fathoms; bottom temperature, 36° "2 ; blue mud; dredged 

 (one specimen). 



Genus 6. Dendrostoma, Grube. 



Longitudinal musculature continuous and not divided into separate bands. The 

 tentacles are united into four to six bundles. There are two free segmental organs, 

 intestine spirally coiled, the intestinal spiral free posteriorly. Hooks present except 

 when they have fallen ofi". Short, compressed, tropical, shore forms. 



13. Dendrostoma hlandum, Selenka and de Man. 



Dendrostoma hlandum^ Selenka and de Man, Die Sipunculiden, &c. {loc. cU.), pp. 85, 86, 

 Taf. i. fig. 9, Taf. xi. figs. 159-162, 1873. 



Body swollen. Proboscis rather short. Skin brownish, of moderate thickness. Un 

 the middle of the proboscis is a zone of numerous, scattered, pointed, black hooks, 

 0*4 mm. in height, and therefore distinctly noticeable even to the naked eye. The whole 

 body is studded with small scattered papillae with a circular base. The tentacles are 

 arranged in five (to six) main bundles. There are two powerful ventral retractors of the 

 proboscis which have their origin in the median third of the body. Two segmental 

 organs completely free. The contractile tube is destitute of villi. 



Habitat — Yokohama (Japan); depth, 5 to 25 fathoms. May 6, 1875. 



The only specimen obtained was found in the same place as those which have been 

 previously recorded, namely, on the coast of Japan. Dr. HUgendorf found the animal at 

 a depth of 4 fathoms. 



