402 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



449.— P:richsoxella filiformis 

 (After Harger). ,■ 5. 



Localities. — Great Egg Harbor, New Jersey; Long Island Sound; 

 Vineyard Sound, Massachusetts; Puntarasa, Florida; Nantucket Sound; 

 Thimble Islands; Fisher's Island Sound; Noank, Connecticut; the 

 Bahamas. 



Depth. — \\ to IS fathoms, in sand and gravel, algte, etc.; low water. 

 Body oblong-ovate, nearly three times as long as wide, 3 nun. : 8 



mm. Length of abdomen equal to a lit- 

 tle more than one-third the length of 

 the entire body, being 3 nun. long. 



Head with front deepl}' excavate be- 

 tween the antero-lateral angles. Antero- 

 lateral angles prom inent and acute. Eyes 

 large, round, composite, and situated 

 about the middle of the head at the ex- 

 treme lateral margins. On the dorsal 

 surface of the head, extending from the 

 anterior to the posterior margins, is a 

 prominent elevation bearing two tuber- 

 cles, one on either side of the median 

 line, which, in a dorsal view, seem to 

 project forward ])eyond the fi'ontal 

 emargination. The lirst pair of antenme 

 have the basal article large and somewhat 

 dilated: the second and third articles are su])equal, and only a little 

 shorter than the first; the fourth article is a little longer than the third. 

 The tirst antenna' extend to the end of the second article of the 

 second antennie. The basal article of the second pair of antennie is 

 short; the second is long, equal to the third article 

 in length, and also equal to the first two articles of 

 the tirst pair of antemia?; the fourth article is nearly 

 twice as long as the third; the fifth is shorter than 

 the fourth, ])eing only about one and a half times 

 longer than the third; the sixth or flagellar article is 

 about as long as the fourth. When retracted, the 

 second pair of antennie extend to the posterior mar- 

 gin of the fifth thoracic segment. The maxilliped 

 has a palp of four articles. 



The second, third, and fourth segments of the tho- 

 rax are a little longer than any of the others, which 

 are sul)equal. In the first two segments the lateral 

 paits are produced in very acute processes, one 

 ])rocess on either side of each segment. Just anterior to this process 

 is the epinieron, which is also acutely produced, but lies underneath 

 the later-al i)()rti<)n of the segment in a lower plane. The epimeron of 

 the second segment is bilobate, the upper division, in a dorsal view, 

 concealing the lower lobe, which is also ver}' acute. The lateral parts 



Kii;. 450.— Erichsox 



ELLA FILIF0RMIS_ 



Maxilliped. >: 51f. 



