among the Shetland Isles. 251 



and Leda is somewhat similar, its disk when expanded resem- 

 bling the leaf of a palm. Another species of Siphonodentalium 

 proper is Dentalium quinquamjulnre of Forbes, from the iEgean 

 (80-230 fathoms), which M'Andrew afterwards dredged off the 

 coasts of Portugal and Spain in 5—30 fathoms, and named 

 (lapsu calami) D. quadrangiilare ; this species Sars lately procured 

 from the Loffoden Isles and Christianiafiord in 50-300 fathoms, 

 and described as *S^. pentagonum. The coincidence of the first 

 and last of these specific names is curious. D. bicarinatum of 

 Deshayes (a tertiary fossil) may also be referable to the genus 

 Siphonodentalium. D. bifissum of Searles Wood, from the Co- 

 ralline Crag, is possibly the type of another genus, for which 

 I would suggest the name of Dischides. This species has been 

 dredged in a living state off Gibraltar by Mr. M'Andrew. I 

 suspected that D. bifissum might be the tube of a young Teredo 

 norvegica, on account of its having a septal process within the 

 posterior orifice : at all events my remark is justified by the 

 affinity which exists between the Teredinidce and the Soleno- 

 conchia. 



The second species of this class is 



Cadulus subfusiformis, Sars 



{Siphonodentalium subfusiforme, 1. c. p. 21, figs. 36-14), having 

 a Norwegian distribution equally extensive with that of S.Lofo- 

 tense, but attaining a greater depth, viz. from 50 to 300 fathoms. 

 I noticed specimens among the fossils collected last year by 

 Messrs. Crosskey and Robertson in a raised sea-bed at Barholmen, 

 near Christiania. It occurred on the Unst ground, in 80-90 fa- 

 thoms, and was apparently not rare. Mr. Peach detected a spe- 

 cimen in looking over some sand which I dredged there in 1864; 

 this I at the time regarded as a Ditrypa. The margin of the 

 posterior orifice has two slight indentations or notches, one on 

 each side; and Sars's statement that the margin is entire was 

 perhaps founded on imperfect specimens. C. subfusiformis may 

 be known from C. gadus not only by its much smaller size, but 

 also by having the greatest width or diameter in the middle 

 (instead of in the upper or anterior part), and by the posterior 

 or narrower part being abruptly curtailed. C. gadus is awl- 

 shaped, and has a tapering extremity. C. subfusiformis is 

 gibbous. Whether C. gadus inhabits our seas is questionable. 

 Montagu says*, "This is a pelagic species, found in many parts 

 of the British Channel, and is known to mariners by the name 

 of 'hake's tooth,' who frequently find it within soundings, 

 adhering to the log-line (as we are informed), but most likely to 



* Test. Brit. i. p, 496. 



17* 



