COPEPODS OF THE WOODS HOLE REGION 623 



86. Ovisacs very long and slender, eggs uniseriate; neither an- 



tennae nor swimming legs present 87 



Ovisacs short and stout, eggs multiseriate; both pairs of an- 

 tennae present, but no swimming legs 88 



87. Metasome coriaceous, with 4 flat processes on each side, which 



are not segmented, but are reticulated; 2 pairs mouth parts; 



on Crustacea 9 Chondrocarpus Bassett-Smith, 1903 



Five free metasome segments, each with a pair of lateral pro- 

 cesses, those on first and second segments 3-segmented; no 

 mouth parts; in actinians 9 Staurosoma Will, 1844 



88. Body short and stout, with 3 pairs lateral and 2 pairs ventral 



processes; first antenna 1-segmented; second antenna pre- 

 hensile; in moUusks 9 Ismaila Berg, 1868 



Body elongate, with 6 pairs of lateral processes; first antenna 

 5-segmented; second antenna 3-segmented, with a stout 

 apical claw; in mollusks 9 Briarella Berg, 1875 



89. Enlarged part a fusion of fourth, fifth, and genital segments, 



with 2 pairs of lateral processes; a third pair on the third 



segment; nasal fossae of fishes 9 Colobomatus Hesse, 1873 



Enlarged part a fusion of second, third, and fourth segments; 

 fifth and genital segments separate, and as narrow as first 

 segment 90 



90. Segments of enlarged part separated by partial grooves; no 



processes; first and second antennae hidden; no caudal rami; 



lateral lines of fishes 9 Leposphilus Hesse, 1866 



Segments of enlarged part completelj^ fused and armed with 



one or more pairs of lateral processes 91 



91. Enlarged part spherical, with 1 pair of processes at its center; 



first antennae 3-segmented; second antennae laminate, 1- 



segmented; frontal canals of fishes 9 Sphaerifer Richiardi, 1874 



Enlarged part trapezoidal, with 2 pairs of processes; a third 

 pair on frontal margin, and a fourth pair on the genital 

 segment; frontal sinus of fishes 9 Polyrrhynchus Richiardi, 1876 



92. First antennae 6-segmented, second antennae 2-segmented; 



exopods of legs 2-, endopods 1-segmented; no third legs; 



frontal sinus of fishes c?" Philichthys Steenstrup, 1862 (p. 531) 



First antennae 4-segmented, second antennae 3-segmented; 

 both rami of legs 2-segmented; third legs uniramose; frontal 

 sinus of fishes cf Polyrrhynchus Richiardi, 1876 



