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



Greenland, 80 fathoms (one specimen, labelled Boltenia clavata), New Zealand (about six 

 specimens, labelled Boltenia pedunculated, M. Edw.), and some others with no locality 

 marked. There are also some specimens in the Liverpool Free Public Museum, from 

 Port Chalmers, Dunedin, New Zealand. They were brought home by Dr. Millen 

 Cough trey, and are labelled Boltenia pedunculate/,. 



In external form this species is rather like Boltenia bolteni, Linn., but they differ in 

 many detads of structure. The above description is taken from the large specimen. The 

 smaller one, which is figured (PI. VII. fig. 6), differs sbghtly in external appearance in 

 several respects, and has the test prolonged into a few short pointed processes scattered 

 here and there over the sides and posterior end, which gives it somewhat the appearance 

 of Boltenia gibbosa, Heller, quite a distinct species. 



One of the most characteristic points in this species is the enormously thick test, of a 

 solid cartilaginous consistency, which suggested the specific name. 



The dorsal tubercle is very peculiar. It is large and circular in outline (PI. VII. fig. 8), 

 while the surface is marked by a number of branched ridges forming an elaborate pattern. 



Two specimens (one large and one small) were obtained from Canterbury, New 

 Zealand. They were presented to the expedition whde at Wellington. 



Culeolus, Herdman. 

 Culeolus, Herdman, Prelim. Rep., Proc. Roy. Soe. Edin., 1880-81, p. 82. 



Body fixed, pedunculated, more or less ovate ; the anterior end, where the long 

 peduncle is attached, narrower than the posterior. Branchial aperture more 

 or less triangular. Atrial aperture bilabiate. 



Test cartilaginous, often very thin, usually rough and papillated on the outer surface. 



Mantle thin ; musculature not greatly developed. 



Branchial Sac with about six longitudinal folds on each side ; consisting of trans- 

 verse vessels and internal longitudinal bars forming a wide meshed network ; 

 there are no stigmata, the fine longitudinal vessels being absent. The larger 

 vessels, especially the internal longitudinal bars, are supported by a system 

 of branched calcareous spicules. 



Endostyle also strengthened by numerous branched calcareous spicules. 



Dorsal Lamina represented by a series of triangular languets. 



Tentacles compound. 



Alimentary Canal relatively small, placed posteriorly on the left side ; stomach ven- 

 tral, intestine turned anteriorly and dorsally, and rectum running posteriorly. 



Genitalia on the inner face of the wall of the peribranchial cavity, developed on 

 both sides of the body. 



As Culeolus is one of the most interesting of the new genera which were collected 

 during the Challenger expedition, I have gone more than usual into detail in the 



