400 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



Legs .slender, with dactyli bi-nnguiculate. 



Color of specimen brown. Lateral edges of thoracic segments 

 colorless. 



One specimen from off Abreojos Point, Lower California, station 

 2835, was collected by the U. 8. Bureau of Fisheries steamer Alha- 

 tross; depth, 5i fathoms. 



Type.— Qui. No. 22580, U.S.N.M. 



65. Genus ERICHSONELLA " Benedict. 



Flagellum of second antenna^ consisting of a single clavate article. 

 The maxillipeds have a palp composed of four articles The epimera 

 of all the segments of the thorax, including the first, are distinctly 

 separated from the segments. The abdomen is composed of a single 

 segment. 



ANALYTICAL KEY TO THE SPECIES OF THE GENUS ERICIISONELLA. 



a. Surface of body smooth throughout. OutUne of body regular. First pair of 

 antennpe short. Terminal segment of body shows but slight traces of a lateral 



tooth near its base on either side ErichsoneUa attenuata (Harger) 



a'. Surface of body tuberculated. Outline of ))ody serrate. First pair of antennic 

 long. Terminal segment of body with a jirominent lateral tooth near the l)ase 

 on either side. 

 b. Large bifid tubercle on center of head. -Median longitudinal row of tubercles 



on each thoracic segment ErlchmncUa filiformis ( Say ) 



y. Large tridentate spine on center of head. INIedian longitudinal row of tuber- 

 cles on each thoracic segment, and a longitudinal row of tubercles on either 

 side of median row on first four thoracic segments. 



ErichsoneUa Jioriddmt Benedict 



ERICHSONELLA ATTENUATA (Harger). 



Erichtifmia atienuahji. Harger with Verrill, Report U. S. Commissioner of Fish 

 and Fisheries, 1873, Pt. 1, p. 570 (276), pi. vi, fig. 27; p. 370(76).— Harger, 

 Proc. U. S. Nat. Mus., II, 1879, p. 160; Report U. S. Commissioner of Fish 

 and Fisheries, LS80, Pt. 6, pp. 356-357, pis. vi, vii, figs. 36-37. 



ErichsoneUa attenuata Richardson, American Naturalist, XXXIV, 1900, p. 228; 

 Proc. U. S. Nat. Mus., XXIII, 1901, p. 543. 



Londitles. — Great Egg Harbor, New Jersey; Noank, Connecticut. 



Bod}' narrow, elongate, six times longer than wide, 2 mm. : 12 nun. 

 Head wider than long, 1^ mm. : 2 mm., with the anterior margin 

 slightly excayate between the antero-lateral angles. Eyes small, com- 

 posite, and situated at the sides of the head, halfway between the 

 anterior and posterior margins. There is a prominent eleyation sit- 

 uated on the head between the eyes. The first i)air of antennte have 

 the basal article large and somewhat dilated; the second article is a 

 little shortei" than the first, and about half as wide; the third and fourth 

 articles are equal in length, and each is one and a half times longer 



a Proposed by Dr. James E. Benedict for the preoccupied Erichsonia. 



