100 MODERN SYSTEM. 



It was observed with young from the middle of June to the 

 middle of July. The females are one-third more abundant than 

 the males. 

 Length an inch and a quarter. 



** Intermediate lamella of the tail entire. 

 Sp. "2. JMi/sis intestra. 

 Praunus integer. Leach, Edin. Encycl.\\\. 401. Mysis Integra. Leach, 



Trans. Linn. Soc. xi. 350.— Sypp. to Encijcl. Brit. i. 4QQ. 

 Inhabits brackish pools of water, left liy the tide at Lock Ranza in the 



Isle of Arran. Common in the month of August with young. 

 Length one third of an inch. 



Females more abundant than the males. Colour whilst living pel- 

 lucid cinereous, spotted with black and reddish brown. 



Division III. — Tail zcith tzroseta-, one on each aide. 



Fam. VI. Neualiad.t. Leach. 



Genus 38. NEBALIA. Leach. 



Thorax anteriorly with a moveable rostrum : anterior pair of legs longest, 

 simple ; other pairs equal, approximate, Avith the last joint bifid : 

 nntcnncE tsvo, inserted above the eyes, the last joint bilid and multi- 

 articulate. 



Sp. 1. Neh. Hcrbstii. Gray or cinereous-yellowish ; eyes black. 



Cancer bipes. 0th. Fubr. Fn. Gion. no. 2'23. Jig. 2. Herbst, ii. tab. 24. 



Jig. 7. INIysis bipes. Latr. Hist. Nat. des Crust, et des Insect, vi. 285. 



Monoculus rostratus. Montagu, Trans. Linn. Soc. xi. 14. tab. 2. fig. 5. 



Nebalia Ilerbstii. Leach, Zool. Miscel. i. 100. tab. 44. — 'Trans. Linn. 



Soc. xi. 33l.—Supp. to Encijcl. Brit. \. 422. 



Inhabits the European Ocean ; it is common beneath stones lying on 

 black mud, on the southern coast of Devon. 



Genus of doubtful situation. 



Genus 39. MEGALOPA, Leach. 



The situation of this curious genus, which is figured in Dr. Leach's 



Malacostruca Brit. {tub. lb?), is still doubtful. It however decidedly 



belongs to the Macrouea, as Dr. L. has discovered to be the case, 



since the publication of the first volume of the Supp. to Enct/el. Brit. 



Legion II. E D R I O P II T II A L M A. 



The Malacostraca Edriophthalma, or at least a greater part of them, 

 were placed amongst the Macroi ka by Latreille, who considered them 

 as forming a particular family of that order. 



Section I. 

 Body laterally compressed* 



