lOO MODLUJ. SYSTEM. 



It Avas 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. Mysis Integra. 

 Praunus integer. Leach, Edin. Enci/cl.vn. 401. Mysis Integra. Leach, 



Trans. Linn. Sue. xi. SoO.—Supp. to Enci/cl. Brit. i. 422. 

 Inhabits brackish pools of water, left by the tide at Lock Ranzain 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 ziiih tu-osctie, one on each side. 

 Fam. VI. Nebaliad.t. Leach. 

 Genus 38. NEBALIA. Leach. 

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

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

 antenna two, inserted above the eyes, the last joint bifid and multi- 

 articulate. 

 Sp. 1. Kcb. Hcrhxtii. Gray or cinereous-yellowish ; eyes black. 

 Cancer bipes. Ofh. Fabr. "Fh. Groti. no. 223. Jig. 2. Hcrbst, ii. tab. 24. 

 fig. 7. Mysis bipes. Latr. Hixt. Nat. dea Crust, et dcs Insect, vi. 285. 

 Monoculus rosU-atus, Montagu, Trans. Linn. Soc. xi. 14. tab. 2.fig.5. 

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

 Soc. xi. 351. — Snpp. to Encycl. Brit. i. 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, Uach. 



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



Malacostraca Brit. {tab. 25.), is still doubtful. It however decidedly 



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



since the publication of the first volume of the Si'pp. to Enci/d. Brit. 



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



Tlie Malacostraca Edriophthahna, or at least a greater part of them, 

 were placed amongst the Macroura by Latreille, who considered theiu 

 as forming a particular family of that order 



Body laterally compressed. 



sr. 

 Section I. 



