88 



Papers from the Department of Marine Biology. 



pointing in wards; palp very broad, 2-jointed. Maxilla 2 normal. Maxilliped 

 inner plate elongate, palp rather long. Gnathopods 1 and 2 similar, nearly 

 the same size, subchelate, palm not so long as in Amphilochus, broad, distal 

 edge rather oblique, broadest part of palm, finger with sharp spine under apex. 

 Perseopods 1 to 5 slender, 3 to 5 with second joint expanded. Telson com- 

 paratively broad with rounded termination. Lateral angles of last abdominal 

 segment as long as telson itself. 



FIG. 5. Cydotelson purpureum gen. et sp. nov. 



A. 

 B. 

 C. 

 I). 

 E. 

 F. 

 G. 

 H. 

 1. 



Whole animal, lateral view. X17, 



Antenna 1. X52. 



Upper lip. X225. 



Lower lip (half). X225. 



Mandible. X130. 



Maxilla 1. X130. 



Maxilla 2. X 130. 



Maxilliped. X52. 



Gnathopod 1. X52. 



K. Gnathopod 2. X52. 



L. Gnathopod 2: finger and anterior edse of palm. 

 X225. 



M. Side plate 4 with first joint of peneopod 2. (Lat- 

 eral plate dotted.) X30. 



X. Peraeopod 4. X30. 



O. Telson and lateral angles of last abdominal seg- 

 ment. X130. 



Cyclotelson purpureum sp. n. 



Side plates vary in serration of loAver and posterior margins: 1 with single 

 serration, 2 with about 10, 3 and 4 with many. Antenna 1 six-jointed with 

 very few sensory setae, no appreciable difference between male and female. 

 Antenna 2 incomplete in specimens examined, but from width of basal joints 

 seems to be distinctly larger than 1. Outer lobe of lower lip with fringe si- 

 setse and an inwardly directed spine. Mandible with third joint of palp dot 

 tirictly longer than 1 and 2 combined, no setae on palp; three small spinules 

 under incisor process. Gnathopods 1 and 2, sixth joint widens gradually of 

 form a convex palm with slightly oblique anterior edge; finger stout, equal in 

 length to front edge of palm, minute serrations behind subapical spine; fifth 

 joint produced to about middle of the palm, process broad; second point pro- 

 duced slightly. Telson width more than half length, apex rather rounded. 



Colour, purple on dorsum. Lives on crinoids. Comanthus annulatum, 

 Murray Islands, Torres Straits. 



