REPORT ON THE AMPHIPODA. 83 



live, flat, and bifid ; the middle one very broad, concealing the others which are capable of 

 spreading laterally. Length, half an inch or more. The female is rather more slender in 

 the body, and does not so suddenly decrease towards the tail. The eyes, as before- 

 mentioned, are distinct, and are of a bright red when alive, reticulated, and marked with 

 two streaks of black, one on each side of the eye, probably the reflection of a pupil. This 

 is another species of Cancer that very nearly approaches the genus Oniscus, and is readily 

 distinguished by the larva-like appearance of its head. It is not uncommonly taken with 

 the last." It should be noticed that this description differs strikingly in some respects from 

 that given of Hyperia galha by Bate and Westwood. Their species is fawn or faint yellow 

 speckled with red, and has green eyes. Montagu's species is olive-green speckled with brown, 

 and has red eyes. Boeck unites both of them as synonyms of Hyperia {Cancer) meduMirum, 

 O. F. Miiller, but does not notice the colouring, nor that in the expression five caudal fins. 

 Montagu attributes to his species only two instead of three pairs of uropods, nor that he 

 gives the long antenna3 to the female instead of the male. Montagu's remark that his 

 species is not uncommonly taken together with Dexamine spinosa, if applied to Hyperia 

 medusarum, seems scarcely in accord with common experience, although various Gammarina 

 are occasionally taken upon Medusx. In the figure, it is the first uropods, not the last, that 

 extend furthest backwards. 



On page 5 he gives "Cancer Gammards Monoculoides. Tab. II. fig. 3." "This species," he 

 says, " seems to connect the Cancer with the Monocidus, but is more allied to the former in 

 the conformation of its members." Its name at present is Stenothoe monondoides. On 

 the same page is given "Cancer Gammarus obtdsatus. Tab. II. fig. 7," now known as 

 Melita oUusata. 



On page 6 he gives " Cancer Gammarus pedatds. Tab. II. fig. 6. Gammarus pedatus. Midi. 

 Zool. Dan. iii. t. 101." He does not seem to have been aware that this had been earlier 

 described by Miiller as Squilla ventricosa. It is now known as Proto ventricma, Miiller. 



JgJ^^LEACH, William Elfoed, bom 1790, died 1836 (Webster). 



Crustaeeology. The Edinburgli Eucyclopsedia, conducted by David Brewster, 

 L.L.D., &c., &c., with the assistance of gentlemen eminent in science and literature. 

 In eighteen volumes. Vol. vii. Edinburgh, m.dccc.xxx. (The issue of the 

 work lasted from 1810-1830, but the title page for each volume bears the date 

 1830. The earlier numbers ran through several editions. Leach's article, 

 Crustaeeology, is referred to by Desmarest, 1825, and others, with the date 

 1813-1814. Whether it originally appeared with or without the appendix seems 

 uncertain.) 



Leach in this article considers that Crustaeeology treats of two classes, Crustacea and Arachnides, 

 as distinct from Insecta. Of Brisson he does not as yet seem to have heard, as he thinks 

 that Pennant first separated the Crustacea from insects, although capriciously. Leach 

 himself takes from the Arachnides the orders Tetracera and Myriapoda of LatreiUe to add 

 them to the Crustacea, and Latreille's Parasita to add them to the Insecta. He divides the 

 Crustacea into three orders, Entomostraca, Malacostraca, Myriapoda ; the Malacostraca into 

 three tribes, Brachyuri, Macrouri, Gasteruri. The Gasteruri are thus defined, " Eyes sessile. 

 The joint of the body which receives the head, of the same size with the rest." This tribe 

 contains the following families, Gnathonii (also spelled Gnathionii), Gammarini, Coroiiliionii 

 (also spelled Corophini), Caprellini, Apseudii. Of these the fii-st, with the genus Gnathia, 



