REPORT ON THE TUNK'ATA. 1(17 



however, in size, and the large one situated close to the dorsal tubercle (tn.) is gigantic 

 compared with the others. The ordinary large ones (tn/) are about twice the breadth of 

 the prsebranchial zone, while the small ones are only one-fourth or one-third of that size. 

 Calcareous spicules are present, bu1 they are noi so numerous as in Culeolus 

 murrayi. 



The Dorsal Tubercle is small, but distinct. It has a cordate form, with both horns 

 turned inwards, and the opening directed towards the right side (PI. X. fig. 6). 



The Peritubercular Area is not so deep as in Culeolus murrayi, and has not such a 

 regularly triangular form. Its depth is about equal to the breadth of the prsebranchial 

 zone on the right (or broader) side (PI. X. fig. 6). 



The Peripharyngeal Band at the edge of the peritubercular area extends further up 

 on the left side than on the right, so as to narrow the prsebranchial zone on that side. 



There is only a single specimen of this handsome species in the collection. It is 

 in most excellent condition, and was dredged in the South Pacific Ocean, to the north of 

 the Kermadec Islands. 



Station 170. July 14, 1874. Lat. 29° 45' S., long. 178° 11' W. ; depth, 630 

 fathoms ; bottom temperature, 4° C. ; hard ground, volcanic mud, and pieces of 

 pumice, &c. 



Culeolus recumbens, Herdman (PI. XI. figs. 1-7, and PI. XII. figs. 1-7). 



Oideolus recumbens, Herdman, Preliminary Report, Proc. Roy. Soc. Edin., 1880-81, p. 85. 



/■'.rfenial Ajipeara nee. — In this species the body is much smaller than in either of the 

 preceding forms. Seen laterally (PI. XL tigs. 1 and 2) its shape is irregularly quadrate 

 with the angles rounded. It is elongated antero-posteriorly and rudely sub-cylindrical, 

 being slightly compressed laterally. Both ends are blunt; the anterior is rather nar- 

 rower than the posterior ; and the posterior is the more convex of the two. The dorsal 

 and ventral edges are nearly parallel, tapering slightly anteriorly ; the dorsal is nearlv 

 straight, while the ventral is a little convex, especially towards the posterior end. 



The peduncle is long, thin, and tough; it is not stiff, as in the last two species, but 

 is very flexible, and in general appearance resembles a piece of thin string. It is attached 

 at the anterior end of the body on the ventral side of the branchial aperture, and in the 

 iii.-i part of its course it runs directly ventrally, so as to leave the branchial aperture 

 exposed, instead of crossing it as in Culeolus murrayi and Culeolus wyville-thomsoni. 

 This directly ventral course is, however, of very short extent (1-2 mm.), as it soon turns 

 abruptly to the right and describes a nearly semicircular curve, and then leaves the 

 surface of the test to which up to this point it has been closely adherent (PL XI. 

 tigs. 1 and 3). It is of uniform thickness throughout, except at the lower end, where 

 for the last few millimetres it becomes slightly thickened, and then break- up into a 



(ZOOL.CHALL.E.\r. — r.VRT xvu. — 1882.) 1. la 



