324 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



ANALYTICAL KEY TO THE SPECIES OF THE GENTS ASTACILLA. 



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

 segment subcylindrical. Terminal abdominal segment with a prominent, 

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



extremity obtuse Astacilla granulata (G. O. 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 abdornofnal segment with a pair of teeth on each side; 

 extremity acute Astacilla cseca Benedict 



ASTACILLA GRANULATA (G. O. Sars). 



Leachia granulata G. O. SARS, Arch. Math. Nat., II, 1877, p. 351 (251). 



Astacilla americana HARGER, Am. Jour. Sci. (3), XV, 1878, p. 374. 



Asiadlla 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. vm-ix, figs. 48-52. HANSEN, Videnskabelige Meddelelser fra den 

 Naturhistoriske Forening i Kj0benhavn, 1887-88, pp. 189-190. BENEDICT, 

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

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

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



Localities. Georges Banks; Banquereau; 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 Norway and 

 Iceland; Grand Banks; latitude 

 60 31' north, longitude 9 18' 

 west; latitude 60 21' north, lon- 

 gitude 5 41' west. 



Depth. 7-640 fathoms. 

 Body narrow, elongate, about 

 six and a half times longer than 

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

 cluding the antennae. 



The head is as wide as long, 2 

 mm. : 2 mm., with the anterior 

 margin deeply excavate. The 

 FIG. 355.-A8TACILLA GRANULATA (AFTER HARGER). eyes are small, round, composite, 



a, FIRST ANTENNA OP MALE. + 4. b, FOURTH an( J situated at the sides of the 



THORACIC SEGMENT OF MALE. + 4. C, VENTRAL 



SIDE OF ABDOMEN. x 4. head, half way between the ante- 



rior and the posterior margins. 



The first pair of antennae 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 antennae. The basal 



