ISOPODS OF THE ATLANTIC COAST— RICHARDSON. 507 



18. GNATHIA ELONGATA (KrjSyer). 



Anceus elongatus Kr0yer, Voy. en[Scand., Crust, pi. xxx, fip;. 3a-o:; Naturh. 



Tidsskr. Nj- R. II, p. 388, 1847. — Hansen, Vidensk. Meddel. iiaturh. Foren in 



Kjoebh., 1887, p. 182. 

 Gnathia elongatn G. O. Saks, Crust, of Norway, II, Pts. 3, 4, j). 55, 1897, pi. 



XXIII, fig. 1. 



Ilahitat. — West Clreenland; iilso coast ofFinmark; Lofoten Islands; 

 Kara Sea. 



Hansen says that it is impossi])le to decide whether Pranzina rein- 

 hardi belongs to this or to another species of Gnathia. Kr0yer's two 

 original specimens have not been preserved, and although in the Co- 

 penhagen Museum there are four specimens of Kr0yer's species iden- 

 tified, it can not be known if one or two of these are the original 

 specimens. 



19. GNATHIA CERINA (Stimpson). 



Praniza cerina Stimpson, Mar. In v. Grand Manan, 1853, p. 42, pi. in, fig. 31.— 

 Verrill, Am. Jour. Sci., VI, 1873, p. 439; VII, 1874, pp. 38, 41, 411, 502; 

 Proc. Am. Assoc, 1873, pp. 350, 354, 358, 362, 1874. 



Anceus americanus Stimpson, Mar. Inv. Grand Manan, 1853, p. 42. 



GnatJiia cerina Harger, Proc. U. S. Nat. Mus., II, 1879, p. 162; Report U. S. Com- 

 missioner of Fish and Fisheries, 1880, Pt. 6, p.410-413, pi. xii, figs. 75-79. 



Habitat. — Bay of Fundy; Massachusetts Bay; ofl' Salem; Gulf of 

 Maine; Casco Bay; Gulf of St. Lawrence. 

 Depth.— 10 to 220 fathoms. 



Family IV. ANTHURID.E. 



analytical key to the genera of ANTHURIDjE.^ 



a. Labium terminating in two rounded lobes. Mandibles with cutting edge of two 



or three Vjlunt teeth, and a semicircular saw in place of molar and spine-row; 



palp three-jointed. First maxillae simple, with apical teeth. Maxillipeds 



with three to six broad flattened joints. 



b. First five segments of abdomen coalesced into single segment in female. 



c. Maxillipeds three-jointed. Flagella of both pairs of antennje few jointed in 



female; of first multiarticulate in male 12. Anfhura. 



cf . Maxillipeds four-jointed. Flagella of both pairs of antennai rudimentarj^, of 



the first pair not greatly developed in male 13. ( 'i/athura. 



b'. Segments of abdomen distinct. Maxillipeds six-jointed 14. Anthdura. 



a'. Labium terminating in two points, acuminate. Mandibles without teeth, lancet- 

 like, lobes at base forming channel. PMrst maxilke spear-like, distally 

 channeled and serrate. Maxillipeds elongate, with four to five joints, the 

 second of wliich is elongate. Abdomen with six segments and telson dis- 

 tinct. Antenuse in both sexes with many-jointed flagella 15. Calathura. 



^Stebbing's key to the Anthuridse has been used as given in Trans. Zool. Soc. 

 Lond., XII, 1886, Pt. 4, pp. 121, 122. 



