96 rROCEEDINGS OF THE NATIONAL MUSEUM. vol. 53. 



ment is abruptly narrowed to less than half that width. The second 

 and third segments each have a pair of lateral cushion processes, 

 as wide as the segment itself and smoothly rounded, those of the 

 third segment having on the posterior ventral surface a small knob. 

 The fourth segment sends out on either side a soft bilobed process, 

 the lobes thick and bluntly rounded, and inclined a little ventrally. 



Behind these lobes the neck narrow^s and becomes rapidly chitinized 

 until it reaches the flexure, beyond which it is slightly enlarged and 

 armed w'ith chitin horns of varying numbers and patterns, but 

 usually short and somewhat flattened. Behind these horns the neck 

 is again narrowed until it reaches the trunk, which it enters exactly 

 on the median line so that there is no distortion of the bilateral 

 symmetry. 



The antennae and mouth parts are at the extreme anterior end of 

 the cephalothorax; the first antennae are stout, three-jointed, and 

 well armed with setae; the second pair are made up of two stout 

 joints, furnished with strong muscles and tipped with a chela, Avhose 

 long and rather slender claw shuts down past a projection on the 

 opposite margin of the terminal joint. The mouth tube is short and 

 but little, if at all, retractile, with a well-defined ventral plate; no 

 first maxillae could be detected; the second pair are three-jointed, 

 the basal joint the shortest, the second joint the longest and stoutest 

 and armed on its outer margin with a short spine; the third joint 

 is tipped with a short and weakly curved claw. Only the two pairs 

 of legs described by Steenstrup and Liitken could be detected ; each 

 of these is biramose and the rami are two-jointed and setiferous. 

 With the three anterior joints of the free thorax so well differentiated 

 we should look for four pairs of legs instead of two, and a perfect 

 specimen will probably reveal them. (See Remarks, below.) 



Color (preserved material) of the body, the soft portion of the 

 neck, and the head grayish yellow, chitinous portions of the neck and 

 egg strings darker orange j^ellow. 



Total length, including curves, 34 mm. Cephalothorax and neck, 

 14 mm. long, 0.75 mm. in diameter. Greatest diameter of trunk, 4 

 mm. Egg coil, 14 mm. long, 2 mm. in diameter. Each egg string, 

 if straightened, would be approximately 125 mm. long. 



(cydopterina, from the genus of fish on which it was first found.) 



Uerriarhs. — Fortunately the specimen numbered 38331 included a 

 mutilated head ; the neck had been broken at the flexure and the an- 

 terior portion was again broken between the cephalothorax and the 

 second segment. But the broken parts could be placed together while 

 they were being drawn, and it was much easier to orient them when 

 thus separated from the trunk than it would have been when attached 

 to it. The antennae and mouth parts were uninjured, but one leg of 



