ISOPODS OF NORTH AMP:RICA. 



67 



Anthura temm Norman and 8tehhing, Trans. Linn. Soc. Loiulon, XII, 1886, 

 Pt. 4, p. 124.^RiciiARDSON, American Naturalist, XXXIV, 1900, p. 215; 

 Proc. U. S. Nat. Muh., XXIII, 1901, p. 508. 



Ptikmthura tenuis Stebhino, Willey's Zool. Results, 1902, p. (519. 



Loealitles. — Noank Harbor, Connecticut; Long Lsland Sound; ofi' 

 Watch Hill, Rhode Island: off Block Island; Wa(]uoit, Vineyard Sound: 

 Ca.sco Ba}^ Maine; Bay of Fundy; 

 Grand Menan, New Brunswick. 



Depth. — Surface to 19 fathoms. 

 Taken on muddy bottom; in sand, 

 mud, and stones; at low water, in sand. 

 Body extremely narrow, elongate, 

 about eight times longer than wide, 

 1 nim.:S^ mm. Head about as wide 

 as long, with the anterior margin tri- 

 angularly produced in a small median 

 process. Eyes small, round, distinct, 

 and situated in the antero-lateral angles 

 of the head. The second pair of an- 

 tennae have the basal article short; the 

 second article is twice as long as the 

 first; the third and fourth are short and 

 subequal, both together being as long fig. 5i.-ptilanthura tenuis (After 

 as the basal article; the fifth is twice harger). a, head with antennae and 

 as long as the fourth; the flagellum is 

 composed of four articles, the first of 

 which is about half as long as the last 

 peduncular article. The second pair 



of antenna* extend to the end of the fourth article of the peduncle 

 of the first pair of antennte. The first pair of antennjv have the first 

 article long; the second and third are subequal and 

 each is a little longer than the first. The first article 

 of the flagellum is very short, about one-third as 

 long as the second peduncular article; the second 

 article of the flagellum is about twice as long as the 

 first. The flagellum is composed of twenty-one arti- 

 cles, which are fui-nished with long haii's. The first 

 antenntB are 2i nun. long. The maxillipcds have 

 a palp of one article. The palp of the mandil)les is 

 composed of one article. 

 The first, second, third, and sixth segments of the thorax are sub- 

 equal, each being 1 mm. in length. The fourth and fifth segments are 

 a little longer. The seventh segment is half a mm. long. 



The first six segments of the abdomen are short, distinct, and sub- 

 equal, with the exception of the last, which is about half as long as 

 any of the five preceding ones. The seventh segment or telson is long 



first thoracic segment (ventral 



side). X 8. 6, Maxilliped. x 50. c. 



First maxilla, d, First pleopod. 



X 20. e, Second pleopod of male. 

 X 20. 



Fig. 52.— Ptilanthura 

 TENUIS. Mandible. 

 X 77i. 



