COPEPODS OF THE WOODS HOLE REGION 609 



41. Anterior corners of genital and fourth segments produced into 



knobs; posterior lobes but no leg rudiments on genital seg- 

 ment; fins of sharks cf Parapandarus Wilson, 1924 (p. 439) 



Anterior corners of genital and fourth segments smoothly 



rounded ; an accessory lobe inside the base of each carapace lobe 42 



42. One pair of rounded lobes at posterior corners of genital seg- 



ment but no leg rudiments; maxillipeds little enlarged, claws 



normal; outside of sharks cf Demoleus Heller, 1865 



Two pairs of pointed lobes and 2 pairs of leg rudiments at cor- 

 ners of genital segment; maxillipeds swollen, with stout for- 

 ceps; fins of sharks cf Pandarus Leach, 1816 (p. 432) 



43. Abdomen 2-segmented; thoracic segments narrower than 



genital segment; third segment wider than second; leg rudi- 

 ments on the genital segment; gill cavity of sharks. 



cf Qangliopus Gerstaecker, 1854 

 Abdomen 1-segmented; thoracic segments wider than genital 



segment ; second segment wider than the third 44 



44. Second and third segments fused, with 1 pair of lateral lobes; 



maxilliped with 2 claws, shutting like scissors; no adhesion 



pads; outside of sharks cf Achtheinus Wilson, 1908 



Second and third segments separated, second with, third with- 

 out, lobes 45 



45. Two pairs of adhesion pads at bases of 2 pairs of antennae; 



genital segment as long as wide, showing no leg rudiments; 



throat of sharks c?" Nesippus Heller, 1865 (p. 438) 



No adhesion pads; genital segment wider than long, with a pair 

 of leg rudiments on its lateral margins near the corners; fins 

 of sharks d^ Perissopus Steenstrup and Liitken, 1861 (p. 424) 



46. Only expods of second and third legs 3-segmented, endopods 



2-segmented; lateral areas of carapace divided as in female; 

 outside of sharks- cf Echthrogaleus Steenstrup and Liitken, 1861 (p. 426) 

 Both rami of second and third legs 3-segmented; lateral areas 

 of carapace entire, not divided; caudal rami large, laminate; 

 outside of sharks <? Dinematura Latreille, 1829 (p. 430) 



47. One or more body regions with plates or wings, or both 48 



Neither plates nor wings on any of body regions 52 



48. All swimming legs transformed into lamellar plates 49 



First 2 pairs of legs of usual form, third and fourth pairs trans- 

 formed into laminae or lacking 50 



49. Carapace covering only part of metasome, without wings; 



dorsal plates on fourth segment covering urosome in female, 

 wanting in male; mouth of sharks, cf 9 Anthosoma Leach, 1816 (p. 446) 

 Carapace covering entire body, with anterior wings; ventral 

 surface also covered by a fused plate; no dorsal plates; 

 operculum of fishes 9 Norion Nordmann, 1864 



50. Third and fourth legs lacking; first 2 pairs 2-segmented; cara- 



pace overlapping anterior thorax but without lateral wings; 



gills of sharks 9 Caetrodes Wilson, 1906 



Third and fourth legs present and variously modified 51 



51. Third and fourth legs flattened laminae; carapace with lateral 



wings; body covered with a single dorsal plate having lobes; 



gills of fishes 9 Sagum Wilson, 1913 



Third and fourth legs with elongate fleshy rami; carapace with- 

 out lateral wings; dorsal body plate single, without lobes; 

 gills of fishes ..,„ cf 9 Lernanthropus Blainville, 1822 (p. 447) 



