ISO PODS OF NORTH AMERICA. 



c' . Basal article of the peduncle of the antennula; very much dilated, seen from 

 below, so prominent that the basal joints of the antennae are placed in a 

 transverse cleft moderately deep between the anteunuhe and the mandi- 

 bles. Last segment of the body ornamented with two large basal tuber- 

 cles situated near the median line. 



d. Fourth and fifth segments of the abdomen a little impressed in the dorsal 

 median line, not ornamented with carinae or tubercles. Last segment of 

 the abdomen with two spines at the apex. 



Exocorallana subtilis (Hansen) 



d'. Fourth and fifth segments of the abdomen with a deep longitudinal exca- 

 vation in the dorsal median line, ornamented with many carinae and 

 tubercles. Last segment of the abdomen with four spines at the apex. 



Exocorallana antillensis (Hansen) 

 a. Eyes very large, contiguous in the middle of the head. 



. Last segment of the abdomen rather short, widely rounded posteriorly and with 

 a median excavation deep and moderately wide. 



Exocorallana fissicauda (Hansen) 

 b' '. Last segment of the abdomen rather long, narrowly rounded posteriorly, with 



no excavation. 



c. Fourth and fifth segments of the abdomen deeply excavate longitudinally in 

 the dorsal median line and ornamented with carinae. Last segment of the 

 body with an incision in the middle of the side and ornamented on the 

 dorsal surface with two densely setose areas and with two large basal tuber- 

 cles situated near the median line Exocorallana oculata (Hansen) 



c f . Fourth and fifth segments of the body very little impressed in the dorsal 

 median line, ornamented with no carinae. Last segment of the abdomen 

 entire at the sides, ornamented on the dorsal surface everywhere with very 

 short hairs remotely scattered Exocorallana u'armingii (Hansen) 



EXOCORALLANA TRICORNIS (Hansen). 



Corallana tricornis HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 379-381, pi. vi, 

 figs. 4-4 p; pi. vn, figs. 1-1 d. RICHARDSON, Proceedings U. S. Nat. Mus., 

 XXIII, 1901, p. 518. MOORE, Bull. U. S. Fish Comm., XX, Pt. 2, 1902, 

 p. 169, pi. ix, figs. 2-5. 



Localities.- Cape Catoche, Yucatan; between Delta of the Missis- 

 sippi and Cedar Keys, Florida; St. Thomas, West Indies; Hucares, 

 Porto Rico; St. Croix, West Indies; Jamaica; Belize, British Honduras; 

 Realejo, Nicaragua, Central America. 



Depth. 24-27 fathoms. 



Body narrow, elongate, three times longer than wide, 4 mm. ; 12 mm. 



Head wider than long, 1 mm. ; 2 mm. with the antero-lateral mar- 

 gins rounded and produced in the middle in a prominent triangular 

 process half a mm. in length, with broad base and apex emarginate or 

 slightly bifid and directed upward, the whole process forming a right 

 angle with the dorsal surface of the head. The eyes are large, con- 

 spicuous, and composite and occupy a large portion of the dorsal sur- 

 face of the head; they are separated from each other by a median 

 groove which extends from the base of the frontal process to the 

 posterior margin of the head. On the posterior portion of the head 

 are two large, prominent tubercles, one on either side of the median 



