518 



BULLETIN" 15 8, UNITED STATES NATIONAL MUSEUM 



Color. — Cephalothorax reddish or blackish from contents of di- 

 gestive tube; trunk transparent cartilage color; oviduct and eggs 

 white and opaque, the latter becoming orange with development. 



Female. — Cephalothorax three to five times as long as the trunk; 

 head not enlarged, covered with a carapace; neck covered with fine 

 transverse wrinkles for two-thirds of its length behind the head. 

 Trunk kidney-shaped, twice as wide as long, flattened on its dorsal 

 surface; ovisacs also kidney-shaped, attached by the center of one 

 side at an angle of 45° to the trunk axis. First antennae 3-seg- 

 mented, armed with stout ensiform spines; second antennae bira- 



mose, the exopod smaller 

 than the endopod; first 

 maxillae tripartite ; sec- 

 ond maxillae apparently 

 attached to the trunk in 

 the sinus of the kidney 

 on the anterior margin. 

 Length of cephalothorax, 

 1.5 mm. ; of trunk, 0.5 mm. 

 Male. — Body ovoid ; 

 pointed anteriorly, the 

 appendages attached to 

 the ventral surface; head 

 with dorsal carapace ; 

 genital process behind the month parts; first antennae 3-segmented 

 and pointed forward; mouth parts like those of the female, ex- 

 cept that the terminal claw of the maxillipeds has a row of minute 

 teeth along its inner margin. Total length, 0.25-0.3 mm. 



Remarks. — This species can be identified by the shape and mode of 

 attachment of the ovisacs and by the profusely wrinkled neck. 



Figure 306. — Clavellisa spinosa: a. Female — head, 

 ventral ; trunk, dorsal ; bj male, lateral 



CLAVELLISA CORDATA Wilson 



Figure 307 



Clavellisa cordata Wilson, Proc. U. S. Nat. Miis., vol. 47, p. 697, pis. 26, 50, 

 52, 1915. 



Occv/rrence. — Both sexes were taken from the gills of the hickory 

 shad {Pomolohus mediocHs) and from the gills of the alewife {Po- 

 molohus pseudoharengus) , captured at Woods Hole by V. N. Ed- 

 wards in October, 1903. 



Distribution. — Not found outside the present area. 



Color. — Body a uniform yellowish white; oviducts and eggs in- 

 clined to pink. 



FeTTiale. — Cephalothorax but little longer than trunk, the same 

 diameter throughout and perfectly smooth; head with dorsal cara- 



