556 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvin. 



(Guerin, 1817), plalessse (v. Beneden, 1870), and the following which were simply 

 named hy Richiardi in 1880, fissus, lepidopi, petersii, serrani, smarts, and trachuri; and 

 lessonianus (Risso, 1816). 



Gayi is here included from a printed figure, the description not having been seen. 

 And finally, the author has been unable to secure either the figures or descriptions of 

 heptapus (Otto, 1821) or hyalinus (Czerniavski, 1868). 



1. Carapace distinctly more than half the entire length 2. 



1. Carapace about half the entire length 25. 



1. Carapace decidedly less than half the entire length 41. 



2. Abdomen four-jointed and shorter than genital segment; the latter quadrate. 



aliuncus, new species, p. 576. 



2. Abdomen two-jointed and longer than genital segment; all males 3. 



2. Abdomen two-jointed, the same length as genital segment 5. 



2. Abdomen two-jointed, shorter than genital segment 11. 



2. Abdomen one-jointed, longer than genital segment 12. 



2. Abdomen one-jointed, the same length as genital segment 13. 



2. Abdomen one-jointed, shorter than genital segment 17. 



3. Abdomen joints about equal bonito, new species, p. 589. 



3. Abdomen joints unequal, the first much the shorter 4. 



4. Genital segment oblong, no wider than abdomen; fifth legs invisible dorsally. 



stromatei (Kroyer, 1863). 

 4. Genital segment quadrate, three-quarters wider than abdomen; fifth legs 



visible, large rufimaculatus, new species, p. 561. 



4. Genital segment barrel-shaped, one-third wider than abdomen; fifth legs 



visible, small schistonyx, new species, p. 564. 



5. Males, fifth legs plainly visible dorsally 6. 



5. Males, fifth legs not visible dorsally 7. 



5. Females, fifth legs not visible dorsally 10. 



6. Genital segment quadrate, half as wide as carapace; fourth legs large, all their 

 spines serrate and a large plumose seta at the tip of the basal joint. 



coryphsense (Steenstrup and Liitken, 1861). 

 6. Genital segment quadrate, half as wide as carapace; fourth legs weak, no serrate 



spines, no seta? thymni (Dana, 1852) p. 603. 



6. Genital segment oblong, one-quarter as wide as carapace; abdomen almost the 



same width, joints equal diaphanas (Nordmann, 1832). 



7. Genital segment oblong, no wider than abdomen 8. 



7. Genital segment obovate or spindle-shaped, from one and a half to twice wider 



than the abdomen 9. 



8. First abdomen joint one-third the second; fourth legs short, just reaching the 



abdomen irritans (Heller, 1865). 



8. Abdomen joints the same length; fourth legs reaching beyond tips of anal laminae. 



longipes (B-Smith, 1898, c). 

 9. Free segment narrower than genital segment; frontal plates narrow, lunules 



small gurnardi (Kroyer, 1863). 



9. Free segment same width as genital segment; frontal plates prominent, lunules 



large ..rapax (Milne-Edwards, 1840), p. 568. 



9. Free segment wider than genital segment; third and fourth legs large and 



stout mulabilis, new species, p. 573. 



10. Genital segment rectangular, wider than long; fourth legs very short; furca 



double fallax (Kroyer, 1863). 



10. Genital segment obcordate, deeply lobed; fourth legs reaching beyond tip of 



abdomen longipes (B-Smith, 1898, c). 



11. Males, genital segment subquadrate; fifth legs visible dorsally. 



teres, new species, p. 649. 



