18 THE VOYAGE OF H.M.S. CHALLENGER. 



The intestine is in loops, and the intestinal spiral exhibits only two coils. The single 

 short segmental organ opens far behind the anus. 



According to Verrill's report, this abundant species is only found in deep water. 



Habitat.— Station 49, May 20, 1873; lat. 43° 3' N., long. 63° 39' W. ; depth, 85 

 fathoms ; bottom temperature, 35° ; gravel, stones ; dredged. 



17. PhascoUon botulus, n. sp. (PI. IV. fig. 20). 



On the posterior third of the body there are scattered rounded-off attaching papillae 

 (Haftpapilleu), measuring 0-3 mm. in their greatest breadth and about 0'12 to 0-18 mm. 

 in height. Two retractor muscles, one very powerful and another weak. Found in 

 Dentalium shells. 



It is impossible for me to give any complete description of this species, since only one 

 imperfectly preserved specimen, 30 mm. long, was available for examination. This 

 animal lay within the shell of a Dentalium, wholly embedded in mud. The intestine was 

 somewhat destroyed by maceration. 



One of the above mentioned papillae, found on the posterior third of the body, is 

 represented in fig. 20. They are distinctly visible to the unaided eye, especially since 

 their brown pigment stands in marked contrast to the thin colourless skin of the body. 



No hooks were to be found. The proboscis was almost completely retracted, in the living 

 animal it was probably longer than the body, measured from the hind end to the anus. 



The tentacles are small and few in number. No exact enumeration was possible. 



The root of the more powerful retractor of the proboscis Avas divided into five ; both 

 retractors originated just in front of the hind end of the body. 



The intestine exhibits a threefold, ascending and descending, loop, and the spiral 

 consists of only two or three coils. The single segmental organ is half the length of the 

 body, and at its very end is bound by mesentery to the body-wall. 



Habitat.— StsLtion 195, October 3, 1874 ; lat. 4° 21' S., long. 129° 7' E. ; depth, 1425 

 fathoms ; bottom temperature, 38° ; blue mud ; trawled. 



18. PhascoUon stromhi, (Montagu) (PI. IV. fig. 21). 



Sipuneulus sfrouihus, Montagu, Trans. Linn. Soc. Lond., vol. vii. pp. 74-76, 1804. 



Sipunciihis hernhardus, Forbes, A History of British Starfishes, London, 1841, pp. 251-253 



(woodcut). 

 SipunculiiH conchanim, Danielssen, Nj't Magaz. f. Naturvidensk. Christiania, 1861, pp. 57, 58. 

 Phascolosoma stromhi, Kef'erstein, Beitrage zur Anatomie und System. Kenntniss dor Sipunculiden, 



Zeitschr. f. wiss. Zool., 1868, Bd. xv. pp. 430-432, Taf. xxxi. fig. 10, Taf. xxxiii. figs. 34-36. 

 PhascolosoiiKi stromhi, Selenka and de Man, Die Sipunculiden, &c. (loc. cif.), pp. 50-53. 



From among the many descriptions of this species, those above given will lie sufficient 

 (see the Bibliography in Die Sipunculiden, Selenka, de Man, and Bidow, pp. 50, 53). 



