REPORT ON THE CTRRTPEDIA. 53 



spines is as follows : there are five pairs along the anterior margin, the first pair very 

 minute, the second pair smaller than the three other pairs, and tufts of, as a rule, three 

 spines on the posterior margin on the limit of two segments. On the seventh and 

 eighth segments of the anterior ramus a single spine is situated nearly in the middle. 

 Pedicels of the cirri not very long, rami rather long and slender ; second segment of the 

 pedicels slightly protuberant, those of the rami not protuberant but elongated. 



Caudal appendages. — Short, not quite one-third the length of the pedicels of the 

 sixth cirrus, terminating rather abruptly and broad, with a row of strong and slender 

 spines at the extremity. 



Ova unknown. 



Size. — The largest specimen collected measures 11 mm., the next largest measures 

 7 mm. 



Number of specimens. — In all six specimens and two extremely small ones, measuring 

 1 mm. only, were collected. 



Habitat. — This species lives attached to the spines of an Echinus, and was dredged 

 at Station 204, November 2, 1874; lat. 12° 43' N., long. 122° 10' E. ; depth 100 and 

 115 fathoms; bottom, mud. (Philippine Archipelago.) 



Conchoderma, Olfers, 1814. 



In the collections made during the cruise of the Challenger, the genus Concho- 

 derma is represented by the species Conchoderma virgatum, Spengler, and by some small 

 specimens which were found attached to a turtle, and which, according to Darwin, is a 

 variety of Conchoderma virgatum. 



As far as our knowledge goes, only two really different forms, true species therefore, 

 can be distinguished in this genus. They are the Conchoderma auritum, Linn., sp., common 

 on whales — when it is often found attached to Coronxdoe — and the above-named 

 Conchoderma virgatum, Spengler. A third species, Conchoderma hunteri, Owen, has been 

 described by Darwin from specimens preserved in spirit in the museum of the College of 

 Surgeons. This may be a different species ; but I think on account of its strong 

 resemblance to the variety Conchoderma virgatum, var. clielonophilus, Leach, and the 

 complete conformity of all its interior characters to those of Conchoderma virgatxim, it 

 would be a great deal more rational to regard it also only as a variety of Conchoderma 

 virgatum. 



Gerstacker (Bronn, " Classen und Ordnungen," loc. cit., p. 535) says that the genus 

 contains five species : besides the three species of Darwin he mentions Conchoderma gracile 

 of the European seas (p. 577), and Conchoderma coronulariwn (p. 578) from the west 

 coast of South America. Of these the first is a species of Heller, who observed it in the 



