No.l5s<o. NEW SPECIES OF CALTGIN.E- WILSON. 601 



toward the tip. In preserved specimens there is a constriction on 

 either side just l)ack of the center, but living specimens show no joint 

 here. 



Anal laminae fairly large, inclined toward each other, each tipped 

 with three short setie. Egg strings wide and considerably longer 

 than the entire })ody, with 50 or 60 eggs in each string. 



Of the appendages the second antenna^ are long and slender, with 

 the terminal claw bent in a half circle near the tip. No first maxillae 

 could be found but there is a small spine on either side in just about 

 the position of these maxilla^ which may be their rudiment. 



The second maxillae are close to the mouth tube, with a broad and 

 swollen base and an abruptly narrowed, slender, and acuminate tip. 

 Upon the base is borne a ]:)apilla armed with two setae, representing 

 the rudimentary endopod. 



The fii'st maxillipeds are of the usual pattern; the second pair are 

 long and slender, the two joints about the same length, the terminal 

 claw bent in a half circle which embraces its entire length. The furca 

 is long and narrow, the central sinus U-shaped, the branches slender 

 and slightly enlarged at their tips. 



The fii'st swimming legs are peculiar in having only a single terminal 

 claw, which, however, is longer than the entire terminal joint and two- 

 thirds as wide, with a blunt tip. 



The basal joint carries a spine on both the anterior and posterior 

 margins at the distal end. The second joint has a single small spine 

 at the distal end on the anterior margin. 



The spines on the exopods of the second legs are unusually large. 

 The rami of the third legs are close together and chiefly noticeable on 

 account of a lack of plumose setae, each ramus having but three. In 

 addition the endo])od carries two spines while the exopod has five. 

 The fourth legs are tlu-ee- jointed with five spines, the four on the ter- 

 minal joint being nearly in a row at the end and all about the same 

 size. 



Total length, 4 mm.; carapace, length, 1.55 mm.; free segment, 0.5 

 mm.; genital segment, 1.15 mm.; abdomen, 0.80 mm.; wddth of car- 

 apace, 1.66 mm.; width of genital segment, 1 mm. 



Color, a transparent horn color, sometimes quite yellow, with small 

 dark purple spots evenly distributed over the dorsal surface. 



{monacanthus, piovog one and aKocvdi] a spine, in allusion j:o the 

 single spine at the tip of the fu'st legs.) 



Young female. — Carapace nearly half the entire length, broadly 

 ovate, wider than long, narrowed considerably anteriorly. Frontal 

 plates wide, distinct, and very prominent; frontal margin with a slight 

 incision at the center, its lateral ends showing a broad curve sweeping 

 forward almost to the edge of the transparent ])order. The latter is 

 corrugated in fine lines on either side of the curve and apparently acts 



