0.1222. ISOPODS OF THE ATLANTIC COAST— RICHARDSON. 511 



16. CIROLANA Leach. 



ANALYTICAL KEY TO THE SPECIES OP CIROLANA. 



. Fifth abdominal segment, with lateral angles free, not covered by fourth segment. 

 h. Body short. Terminal abdominal segment tricarinatcd. Inner branch of 

 uropoda much longer than outer branch. First pair oi antennie 

 short, reaching only posterior margin of head; second jiair not 

 armed with brushlike structure on flagellum. Sides of head 

 angulated. Frontal lamina forming a large, rounded projection, 

 extending beyond the apex of the head, and separate from the 



frontal process 25. Cirolana Kphrcrnmiformis Hansen. 



I/. Body elongate, ovate. Terminal abdominal segment smooth. Inner branch of 

 uropoda shorter than outer branch. First pair of antennae long, 

 reaching the posterior margin of the first thoracic segment; second 

 pair armed with a brushlike structure on flagellum. Sides of head 

 rounded. Head produced in front, contiguous with frontal lamina. 



26. Cirolana mayana Ives. 

 '. Fifth abdominal segment, with lateral angles covered by the fourth segment. 

 b. Frontal lamina laosteriorly or clypeus anteriorly produced hornlike, especially 

 so when seen from the side. 

 c. First i^air of antennfe short, reaching only to the posterior margin of the head. 

 Without indications of four low tubercles on head. Terminal abdom- 

 inal segment armed with eight spines ... 27. Cirolana minuta Hansen. 

 (/. First pair of antenn;e long, reaching the posterior margin of the first thoracic 

 segment. With indications of four low tubercles on head. Terminal 

 abdominal segment without spines, crenulate on its posterior mar- 

 gin 28. Cirolana virginiana Richardson. 



>^'. Frontal lamina and clypeus unarmed, not produced horn-like; anterior mar- 

 gin of the clypeus connected with the frontal lamina, 

 c. Frontal lamina narrow, elongate, from four to six times longer than broad. 

 d. Extremity of exterior margin of inner branch of the uropoda emarginate. 

 e. Terminal segment emarginate at its extremity. 



29. Cirolana concharmn. (Stimpson). 

 e^. Terminal segment not emarginate at its extremity. 



30. Cirolana impregsa Harger. 

 d'. Extremity of exterior margin of the inner branch of the uropoda not 

 emarginate. 

 e. Second pair of antennae long, extending beyond the posterior margin of 

 the third thoracic segment. 

 /. Eyes small, black, longer than wide. Branches of uropoda narrow, 

 lanceolate, somewhat elongated; inner branch almost three times 

 longer than wide. Clypeus smooth, even. Terminal segment pos- 

 teriorly rounded 31. Cirolana borealis Lilljeborg. 



f. Eyes large, brown, as long as wide. Branches of uropoda short; inner 

 branch hardly twice longer than wide. Clypeus with margin raised 

 all around and in the middle, surrounding two impressed areas. Ter- 

 minal segment truncated oliliquely with apex acute. 



32. Cirolana gracilis Hansen. 

 e'. Second pair of antennjc short, reaching the middle of the first thoracic 



segment 33. Cirolana polita (Stimpson). 



(/. Frontal lamina broad, short, scarcely twice as long as wide. 



d. Terminal segment truncate 34. Cirolana obtruncata, new species. 



d\ Terminal segment not truncate, rounded. 



