234 CLASS vii. 



the posterior extremity infundibuliform with margin usually denti- 

 culate. A membraneous tube covered with fragments of shells, open 

 at both ends, including the animal. 



Sp. Clymene amphistomaSAV. Descr. deVEgypte, Annil. PL i. fig. i; GUE"RIN, 

 Iconogr., Annel. PI. 10, fig. i, from the Ked Sea. See fig. of other species, 

 Cuv. R. Ani. td. ill, Annel. PI. 22. 



B. External organs of respiration. 

 * Tubulate. 



Note. The Cephalobranchiate, or tubicolous EDW. Anmdata, are 

 more imperfect than the roving or notobranchiate. It seems right 

 therefore to introduce them here, although the affinity by which 

 Arenicola is connected with the Lumbricini points to a different 

 arrangement. 



Family VI. Amphitritce SAV. Head not distinct, eyes none, 

 body usually encased in a tube. 



A. Branchiae anterior, more or less composite, with one, two 

 or three pairs. 



Siphonostoma OTTO. Two larger tentacles (branchiae ?) and seve- 

 ral soft cirri around the mouth. Fasciculi of setae in double pairs 

 in every segment ; the setae in the anterior segments extremely long, 

 directed forwards, glistening with gold. The worm not included in 

 a tube. 



Sp. Siphonostoma diplochaitus OTTO Nov. Act. Acad. Natur. Curios. Tom. x. 

 i, 1821, p. 628, Tab. 51, in the Mediterranean at Naples; other species 

 have been described by MILNE EDWARDS, GRUBE and RATHKE ; see 

 RATHKE Beitr. zur Fauna Norwegens, Nov. Act. Acad. Natur. Curios. 

 Tom. xx. i, 1843, pp. 211219, Tab. xi. 



To the same division also appears to belong the worm described by 

 ABILDGARD in the Zoolog. danic. Tab. 90, as Amphitrile plumosa, but 

 which differs from Amphitr. plumosa of O. FABRICIUS (Fauna grcenl. 

 p. 288) ; OKEN formed from it the genus Pherusa 1 , (Lehrb. d. Zoolog. i. 

 s. 377) : Siphonostoma plumosum RATHKE Beitr. zur vergl. Anat. u. Physiol. 

 1842, p. 84, Tab. vi. figs, i 7, Beitr. zur Fauna Norwegens, p. 208, Tab. 

 XI. f. i, 2. 



1 The name Pherusa was also given by LAMOUROUX to a genus of the class of 

 Polyps, of which the polypary alone is known and to which Flustra tubulosa belongs ; 

 Hist, des Polypiers flexifoles, 1816, p. 117 ; G. JOHNSTON formed from Amph. plumosa 

 the genus Flemingia, from which his genus Trophonia does not differ. Ann. of Nat. 

 Hist. xvn. p. 294. 



