80 PROCEEDINGS OF THE NATIONAL, MUSEUM. vol. 60 



first maxillae filiform ; second pair with a swollen basal joint, a slen- 

 der second joint, and a short spine-like terminal joint or claw. The 

 outer margin of the second joint and the terminal claw are armed with 

 minute teeth. 



The maxillipeds are the characteristic appendages of this species. 

 The basal joints are enlarged so as to occupy the entire sides of the 

 cephalothorax, reaching forward to the bases of the second antennae 

 and projecting backward outside of the narrowed cephalothorax be- 

 yond the anterior margin of the second segment. Each basal joint 

 is apparently made up of two parts, posterior and anterior, separated 

 by a well-defined groove. The posterior part carries the long, slender, 

 and strongly curved terminal claw, while the anterior part is like a 

 large pad with a rounded tip. Both parts carry a heavy fringe of 

 hair, that on the anterior part being twice the length of that on the 

 posterior. The swimming legs are reduced to mere vestiges ; the first 

 pair are represented by tiny knobs on the ventral surface of the 

 cephalothorax inside the bases of the maxillipeds. The second pair 

 appear as a bilobed lamina on either side of the second segment. 

 The third pair are short, flattened laminae on the third segment, while 

 the fourth pair are entirely lacking. None of the legs have either 

 spines or setae. 



Color a light flesh red, the convolutions of the oviducts along the 

 sides of the posterior body a dark brown, separated into stripes by 

 transverse bands or dorsoventral muscles. Prehensile claws yellow, 

 tipped with dark red. 



Total length, 5 mm. Greatest diameter, 0.75 mm. Egg strings 4.50 

 mm. long, 0.25 mm. wide. 



SpecifiG characters of nauplius. — General shape an elongated cone, 

 the bluntly pointed end postei-ior. The first antennae carry the 

 usual pair of plumose setae and also a pair of stout spines at the 

 base of the setae, on the posterior distal corner of the terminal joint. 

 The exopods of the second antennae and mandibles carry four plu- 

 mose setae, the endopods two. The endopods of the second antennae 

 are longer than the exopods and are armed at their tip with a stout 

 claw, between the bases of the setae. The endopods of the mandibles 

 are much shorter than the exopods and unarmed. 



The balancers are long needle-like spines, extending laterally at 

 right angles to the body axis, so that the two fall in the same 

 straight line. 



At the posterior end of the body can be seen, inside of the skin, 

 the tips of the appendages of the future metanauplis. 



Color.— ThQ dark mass of pigment in the center of the body is 

 brown, the surrounding tissues are grayish white. 



Total length, 0.25 mm. Width through the bases of the mandibles.. 

 0.10 mm. 



