COPEPODS OF THE WOODS HOLE REGION 281 



Family MACROSETELLIDAE 

 vienus MACROSETELLA A. Scott, 1909 



Body slender and cylindrical or slightly compressed; head fused 

 with the first segment; urosome 4-segmented in female, 5-segmented 

 in male; genital segment divided; caudal rami slender, cylindrical, 

 longer than the last two abdominal segments combined, and closely 

 appressed, apical setae much longer than the entire body. 



First antennae 9-segmented, geniculate in the male; exopod of 

 second antenna wholly lacking; exopods of first four pairs of legs 

 3-segmented, endopods of first legs 2-segmented, of the three follow- 

 ing pairs 3-segmented in the female ; in the male the second endopod 

 is 2-segmented, the third and fourth endopods 3-segmented; fifth 

 legs 2-segmented ; a single ovisac. 



KETX" TO THE SPECIES (BOTH SEXES) 



1. Frontal margin of head without cuticular lenses gracilis (p. 281) 



Frontal margin of head with two cuticular lenses oculata (p. 283) 



MACROSETELLA GRACILIS (Dana) 



FiGUKE 174 



Setellot gradlis Dana, United States Exploring Expedition, 1838-1842 (Wilkes), 

 vol. 14, Crustacea, p. 1198, 1853, pi. 84, fig. 3, 1855.— Giesbbecht, Fauna und 

 Flora des Golfes von Neapel, vol. 19, p. 559, pis. 1, 45, 1892. 



Occw^ence. — Ten specimens, including both sexes, were taken in a 

 vertical net at Station 20049, Grampus, March 10, 1920 ; also reported 

 from six other stations in the Gulf of Maine, most of them within the 

 present area. 



Distribution. — Mediterranean (Giesbrecht); Atlantic Ocean 

 (Cleve) ; Malay Archipelago (A. Scott) ; Messina (Glaus) ; Gulf of 

 Guinea (T. Scott) ; Papua, Philippines, Sandwich Islands, Atlantic 

 and Pacific (Brady) ; Indian Ocean (Thompson and Scott) ; North 

 Sea (van Breemen) ; Gulf of Genoa (Brian) ; Gulf of Maine (Bige- 

 low) ; Gulf Stream south of Marthas Vineyard (Wheeler). 



Color. — Body in general very transparent; chitin covering and 

 proximal portions of all the appendages pinkish violet; digestive 

 canal ferruginous red, surrounded by oil drops, which are usually 

 yellow and darker in color anteriorly; eye bright ruby red. 



Femnole. — First antennae very long for an harpactid, reaching the 

 genital segment; second antennae 3-segmented, the exopod entirely 

 lacking ; mandibles and maxillae very rudimentaiy ; maxillipeds well 

 developed, second segment much longer than the first, terminal claw 

 less than half as long as the second segment. Rami of the swimming 



