602 BULLETIN 159, UNITED STATES NATIONAL MUSEUM 



32. Exopods of first 4 pairs of legs 3-segmented; first endopod 1- or 



2-segmented; second, third, and fourth endopods 2- or 3- 



segmented; in ascidians cf Botryllophilus Hesse, 1864 (p. 392) 



Exopods of first 4 pairs of legs 3-segrQented, endopods 2-segmented 33 



Exopods of first 4 pairs of legs 2-segmented, endopods 1-segmented 34 



Odd combination of segmentation and absence of rami 35 



33. Metasome segments of female produced into dorsal and lateral 



processes; first antennae 8- or 9-segmented; caudal rami 



unciform; in ascidians cT ? Notopterophorus Costa, 1829 



Metasome segments without processes, but with epimeral 

 plates; first antennae 12-segmented; caudal rami normal, 

 with apical setae; in ascidians 9 Platy thorax Hesse, 1866 



34. Brood pouch covering entire thorax; urosome reduced to a 



single segment; first and second antennae 3-segmented, 



nonprehensile; in ascidians 9 Buprorus Thorell, 1859 



Brood pouch not covering first segment; urosome 5-segmented; 

 first antennae 2-segmented; second antennae 3-segmented; 

 fifth legs squamate; in ascidians 9 Campopera Schellenberg, 1921 



35. Exopods of first 4 pairs of legs 3-segmented; first endopod 3- 



segmented, second and third endopods 4-segmented, fourth 

 endopod 2-segmented; last 3 no setae; in ascidians. 



9 Gunentophorus Costa, 1840 

 Exopods of first and second legs 3-segmented, endopods 1- 

 segmented; third legs uniramose, 2-segmented; fourth and 

 fifth legs lacking; second antennae 4-segmented; on annelids. 



9 Gastrodelphys Graeflfe, 1883 

 Rami of first and second legs 1-segmented, other pairs reduced or 



lacking 36 



36. Third legs each reduced to a tiny papilla, fourth and fifth legs 



lacking; first antennae 3-segmented; second antennae 



3-segmented, with 4 claws; on annelids 9 Nereicola Keferstein, 1863 



Third, fourth, and fifth legs lacking; first antennae unsegmented 

 stumps, with short spines; second antennae in female 1-seg- 

 mented, in male 3-segmented; in Balanoglossus cf 9 Ive Mayer, 1879 



37. First 4 joairs of legs present, fifth pair lacking 38 



First 2 or 3 pairs of legs present, the others lacking 44 



All 5 pairs of legs lacking 46 



38. First 4 pairs of legs 4-segmented; first and second antennae 



each 3-segmented, the latter with 2 small apical claws; caudal 



rami without setae; in ascidians 9 Narcodina Wilson, 1924 



First 4 pairs of legs with less than 4 segments 39 



39. Body cyhndrical; legs not sheathed in a basal capsule; urosome 



not segmented, metasome more or less distinctly segmented 40 



Body moderately depressed; legs sheathed in a basal capsule; 



both metasome and urosome rather distinctly segmented 42 



40. Anus dorsal, in groove between metasome and urosome; first 



and second antennae 2-segmented; legs truncated cones, 

 2-segmented, 2 end claws; in ascidians 9 Mychophilus Hesse, 1865 



Anus in normal position, terminal; urosome shorter than meta- 

 some; legs conical, 1-segmented or 2-segmented; second 

 antennae prehensile; in ascidians 9 Enteropsis Aurivillius, 1885 



Anus in normal position, terminal or terminodorsal; urosome 

 longer than metasome 41 



