110 AMPHITRITE CIRRATA. 



the main fang, and the posterior outline curves forward to the crown, and has a 

 projecting process of the base inferiorly. The base has a gentle curve, slopes from 

 behind downward and forward, and an eminence occurs on the anterior curve below 

 the main fang. Striaa pass from the teeth on the crown to the posterior border of the 

 neck. The broad ridges for the hooks are large in the bristled region, but thereafter 

 they diminish to short lamellae, and then low ridges toward the tail. The posterior 

 hooks have smaller (shorter) bases and the posterior outline is less curved toward 

 the crown. 



There are several varieties of hooks. Thus (1) in those from South Devon the curve 

 of the back of the hook and the base forms a semicircle, as Malmgren shows ; this is a with 

 four teeth above the main fang. The anterior ligament is considerably within the tip 

 of the main fang. (2) b, in which the posterior curve differs, the base being shorter, the 

 posterior projections greater and the curve more abrupt. This resembles Malmgren 5 s 

 groenlandica. The outline of the hook differs. 



A variety of AmpMtrite cirrata occurred in the " Porcupine " Expedition of 1870, 

 Station No. 3 in 690 fathoms, in w T hich there is a tendency to the shortening of the 

 line from the anterior process (below the main fang), and a distinct hollow immediately 

 beneath the process, thus approaching A. a finis. Its branchias are unbranched, or perhaps 

 only a single one is split. 



The small size of specimens from Bressay Sound is in contrast with that of those from 

 the south. 



This species was entered by Linngeus (1767), along with Terebella lapidaria, but it 

 was 0. F. Miiller (1771) who gave the name Ampthitrite cirrata. Considerable confusion 

 existed in connection with the Terebellids and the Amphictenidas until the labours of 

 0. F. Miiller, Fabricius (1780), Savigny (1820), Montagu (1818) and Risso (1826) rendered 

 it possible to place them on a more satisfactory footing : indeed Lamarck's classification 

 (1812) rather increased the complexity, since the Pectinarians and Sabellarians were joined 

 with the Terebellids. 



Montagu's specimens from South Devon reached the length of 12 inches, and he 

 describes them as gregarious in tubes of sand and clay, half an inch projecting from the 

 surface. The branchiae in the figure are ramose, but probably this was due to the artist. 

 His Amphiro cirrata 1 as figured by Miss D'Orville is probably the same form though the 

 branchiae are somewhat confused. It has seventeen pairs of bristles. This author's 

 Amphiro foetida 2 has branchiae apparently unbranched, but differs from A. cirrata in having 

 bristle-tufts almost to the posterior end. 



Chenu (1843 — 53) figures this species, but he shows only nine pairs of bristles 

 anteriorly, so that there is doubt. 



The form which Dalyell (1853) describes as Terebella conchilega, the shell-binder, 

 appears to be an Amphitrite, and probably this species, though his artist has given 

 it bristle-tufts from front to rear. He found the reddish ova discharged from September 

 to December. His form made its tube of comminuted shells, though in confinement one 

 used sand. 



1 MS. vol. 'Linn. Soc./ 1808, pi. xxviii, ^g. 1. 



2 Ibid., pi. xl, fig. 3. 



