328 DESCRIPTION OF A • 



lamella caudalis media) apice fisso interniedias fere 2>^rvenit 

 lamellas ; Jissura hrevis. 



Colour very variable — whitish, ashy, green or brown of various 

 shades. Carapace cylindrical. Eostrum short, triangular, not 

 exceeding one-third the length of the eye peduncle. Antennal 

 scale oblong lanceolate, with an obliquely truncate apex, three 

 times the length of the eye, and more than twice that of peduncle 

 of the internal antennae; a spine at the apex of the exterior 

 margin, which is not ciliated; interior margin and apex densely 

 ciliated. Antennce long and slender. Telson about as long as the 

 intermediate laminae ; bifurcate about one-tliird of -its length. 



The most widely diffused species on our coasts. Common in 

 rock pools. 



Mysis Lamornj]], R. Q. Couch. (PL XVIII., figs. 4, 5.) 



Mf/sls Lamonice. Couch in " Zoologist" (1856), p. 5286. 



Mysis crassus, sanguineus vel aurantius. Thorax pone lateribus 

 multum dilatatis. Abdomen lateribus fere parallelis^ segmen- 

 tisque suba^qualibus. Appendix antennarum squamiformis 

 obovata, brevis, utrinque dense ciliata, nulla spina munita. 

 Thoracis frons breviter rostrata. Pedunculi oculorwn perbreves, 

 attamen appendicis antennarum brevis plus quam dimidium 

 superantes. Antenna? prcelonga?. Telson ad apicem atqueper 

 longitudinis tertiam fssum, breve, intermediarumque dimidium 

 lamellarum tantum attingit. 



Colour " arterial blood" or orange. 



Carapace greatly widening behind, and " more enlarged poste- 

 riorly than in any other long-tailed crustacean." — (Couch.) Ab- 

 domen of nearly equal diameter throughout. Rostrum short, tri- 

 angular, one-third the length of the remarkably short peduncle 

 of the eye. Antennal scale ovate, with the apex rounded, very 

 short, slightly exceeding the length of the peduncle of the 

 internal antennae, ciliated all round; no spine on the outer margin. 

 Antennx long. Telson short, half as long as the intermediate 

 laminae ; the bifurcation through half its length. 



