324 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



ANALYTICAL KEY TO THE 8PECIES OF THE GENUS ASTACILLA. 



a. With eyes. Head excavate in front, without rostriforin point. Fourth thoracic 

 segment suhcyhndrical. Terminal abdominal segment with a prominent, 

 subacute tooth on each side above the middle, directed outward and backward; 



extremity obtuse Astucilla granulata (G. 0. Sars) 



a^. Without eyes. Head with a rostriform point in front, between the antennulse. 

 Fourth thoracic segment wider at the anterior end, and tapering to the poste- 

 rior end. Terminal abdomonial segment with a pair of teeth on each side; 

 extremitv acute A.stacilla cscca Benedict 



ASTACILLA GRANULATA ( G. O. Sars). 



Leachi a granulata G. O. Sars, Arch. Math. Nat., II, 1877, ]). 351 (251). 



Astacilla americanu Haeger, Am. Jour. Sci. (3), XV, 1878, p. 374. 



Astadlla granulata Harger, Proc. U. S. Nat. Mus., II, 1879, p. 161. — Sars, 

 Norw. North Atlantic Exp., Crust., 1885, p. 107, pi. ix, figs. 27-35.— Har- 

 ger, Report U. S. Commissioner of Fish and Fisheries, Pt. 6, 1880, pp. 364- 

 367, pis. viii-ix, figs. 48-52. — Hansen, Videnskabelige Meddelelser fra den 

 Naturhistoriske Forening i Kjobenhavn, 1887-88, pp. 189-190. — Benedict, 

 Proc. Biol. Soc. Washington, XII, 1898, p. 50. — Richardson, American Nat- 

 uralist, XXXIV, 1900, p. 230; Proc. V. S. Nat. Mus., XXIII, 1901, p. 550.— 

 Norman, Ann. Mag. Nat. Hist. (7), XIV, 1904, p. 448. 



Localities. — George.s Banks; Banquereati; Miquelon Island, south 

 of Newfoundland; latitude 69'^ 16' north, longitude 58° 8' west; 

 latitude 70° north, longitude 58° 38' west; latitude 71° 10' north, 

 longitude 58° 56' west; latitude 72° 41' north, longitude 59° 50' 



west; also between Noi'way and 

 Iceland; Grand Banks; latitude 

 60° 31' north, longitude 9° 18' 

 west; latitude 60° 21' north, lon- 

 gitude 5° 41' west. 



Depth.— 1-UO fathoms. 

 Body narrow, elongate, about 

 six and a half times longer than 

 wide, 2i mm. : 16 mm., not in- 

 cluding the antennae. " 



The head is as wide as long, 2 

 mm. ; 2 nun., with the anterior 

 margin deeply excavate. The 

 e3^es are small, round, composite, 

 and situated at the sides of the 

 head, halfwaj^ between the ante- 

 rior and the posterior margins. 

 The first pair of antenna; have the basal article long and somewhat 

 dilated; the two following articles are short and slender, the two 

 together being as long as the first article; the fourth or last article is 

 a little longer than the first. The first antennae extend to the end of 

 the second article of the peduncle of the second antenna?. The basal 



Fig. 355.— Astacilla granulata (After Harger). 

 a, First antenna of male. + 4. h. Fourth 



THORACIC SEGMENT OF MALE. + 4. C, VENTRAL 

 SIDE OF ABDOMEN. X 4. 



