444 THE ANNELIDA POLYCHAETA. 



g. Prostomium with a prominent tubercle at each anterior corner above; uncinus (in 

 type) with eight teeth and a process in the interval above the inferior process. 



Saniythopsis Mcintosh. 

 gg. Prostomium with no tubercle at each anterior corner; uncinus (in ts^pe) with but 

 five teeth and with no process in the interval above the inferior process. 



h. With three pairs of branchiae Samytha Malmgren. 



hh. With four pairs of branchiae Amphisamytha Hessle. 



//. Eighteen somites bearing capillary setae; four pairs of branchiae Paiwa, gen. nov. 



Because of the incompleteness of the description given by Mcintosh 

 (Challenger AnneUda, 1885, p. 441, pi. 27A, fig. 18) of Melinnopsis atlantica, 

 type and only known representative of the genus, the position of that form is 

 somewhat doubtful. No mention is made of postbranchial spines and it is 

 assumed that they are absent. If the form should really prove to belong in the 

 group with Melinna, its place in the key would be with Oeorpata, from which 

 it would be readily separable in having its branchiae simple. 



Eusamytha Mcintosh (1885) is not included in the key because its separa- 

 tion from Samythella Verrill (1873) is not sufficiently clear, Verrill giving neither 

 description nor figure of the uncinus, and Mcintosh likewise omitting some 

 important points and giving no generic diagnosis. The types of both genera, 

 padfica and elongata respectively, have the number of somites larger than usual 

 in the Samythinae. 



Ampharete Malmgren. 



Ofvers K. vet. akad. Forh., 1865, p. 362. 



Branchiosabella Claparede, Beobacht. anat. entw. wibell. thiere, 1863, p. 34. 



Anoholhrus Levinsen, Ofvers. Nordiske Annulata, 1883, pt. 2, p. 161, 165. 



Ampharete homa, sp. nov.^ 

 Plate 77, fig. 7, 8. 



The color at present is dusky brown, with prostomium and peristomium 

 appendages, etc., yellowish. 



The body anteriorly is of but moderate width, is cylindrical, and of uniform 

 width and depth. It is more slender posteriorly, but similarly cylindrical and 

 uniform caudad of the middle, excepting at the caudal end, which is pointed. 

 The total length is 39 mm., and the diameter in the anterior region 2.5 mm. 

 There are fourteen setigerous somites and twelve in the abdominal division. 



The prostomium is much depressed below the level of the dorsum of the 



' bfxbs, miiform. 



