402 



BULLETIN -54, UNITED STATES NATIONAL MUSEUM. 



FIG. 449. ERICHSONELLA 

 (AFTER HARGER). 



FILIFORMIS 

 x 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, algae, etc.; low water. 

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



mm. Length of abdomen equal to a lit- 

 tle more than one-third the length of 

 the entire body, being 3 mm. long. 



Head with front deeply excavate be- 

 tween the antero-lateral angles. Antero- 

 lateral angles prominentand 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 beyond the frontal 

 emargination. The first pair of antenna* 

 have the basal article large and somewhat 

 dilated; the second and third articles are subequal, and only a little 

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

 The first antenna? extend to the end of the second article of the 

 second antenna?. The basal article of the second pair of antenna? is 

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

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

 the first pair of antennae; the fourth article is nearly 

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

 the fourth, being 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 antenna? 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 

 arc .subequal. In the first two segments the lateral 

 parts are produced in very acute processes, one 

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

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

 the lateral portion 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 very acute. The lateral parts 



FIG. 450. ERICHSON 

 ELLA FILIFORMIS 

 M A X I LLIPED. X 51|. 



