CRUSTACEOLOGY. 



403 



•Rubric*- 



Ol3. 



5G. Mjera. 



Rrouima- 

 Ha. 



57. Miu< 



T*. 



Palmata. 



hewly sunk well, in the square of St Bartholomew's 

 hospital, London, by Thomas Wheeler, Esq. apothe- 

 cary to that institution, who sent it to Mr Leach, in 

 •whose collection it is now preserved. It is very pro- 

 bably a young animal ; it differs principally from Gam- 

 mams pule.x, in having the upper process of the tail 

 much longer. The colour, when alive, was cinereous, 

 bat so translucent, that the eyes could not be discover- 

 ed ; it stands in Mr Leach's cabinet, under the specific 

 name subterrnneus, as it most probably inhabits springs 

 under the earth. 



** Marine. 

 Sp. 2. Locustu. Eyes lunated and placed in a line 

 with the superior antenna ; back near the tail with fasci- 

 culi of spines. 



Cancer locusla of Linne. Is it Cancer gammarus lo- 

 cus! a of Montagu ? Linn. T'rans. vol. ix. 



Inhabits pools left by the tide, on all the rocky shores 

 of Great Britain. 



Length of the male an inch. 



Sp. 3. Canvjlops. Eyes shaped like the capital let- 

 ler S, extending from the upper part of the superior to 

 the upper part of the base of the inferior antennae. 

 Back near the tail with fasciculi of spines. 



Discovered on the shore of Arran, by Mr Leach, 

 who named it, from the flexuous shape of the eyes, G. 

 camylops. 



Length of the male half an inch, female somewhat less. 

 Mas. Leach 



Sp. 4. Rubricates. Eyes angulated ; situated between 

 the superior and inferior antennae. 



Cancer gammarus rubricates of Montagu. Ampiihoe 

 rubricata, Leach's MSS. 

 Length half an inch. 

 Inhabits Britain. 



Discovered by George Montagu, Esq. and well de- 

 scribed by him in the Transactions of the Linnean So- 

 mety, vol. ix. Colour, when alive, usually reddish, or 

 pale pink, minutely and closely speckled with spots of 

 a darker shade. Eyes crimson. It is a rare species, 

 and possibly does not belong to this genus. 



Genus LVI. Mjera. Anterior pair of feet with 

 a moveable nail ; the second pair with a compressed 

 hand and moveable thumb. Peduncle of the antennae 

 with three joints ; the superior antennas longest. 



Sp. I. Grossimana. Body smooth, with eleven joints; 

 superior antennae nearly as long as the bod)'. Internal 

 edge of the palm of the second pair of feet ciliated, 

 having a slight groove to receive the thumb. 

 Length five lines. 



Colour, when alive, pale yellow, sometimes mottled 

 With pink. 



Cancer gammarus grossimanus of Montagu. Mcera 

 grossimana. Leach's MSS. 



Inliabits pools left by the receding tide, on all our 

 rocky shores. 



Genus LVII. Melita. Anterior pair of feet very 

 small ; second pair with a compressed hand, and move- 

 able nail which bends on the palm. Superior styles of 

 the tail very long and large. 



Sp. 1. Palmata. Blackish; the tail above, with a 

 few spines. 



Inhabits the rocky shores near Plymouth in Devon- Crustacea, 

 shire. *""* 



Gammarus palmata, Montagu, Linnean Transactions, 

 vol. vii. tab. o. Melita palmata, Leach's MSS. 



Genus LVIII. Leucotiioe. Anterior feet with 38. Ltw- 

 a finger and thumb ; the thumb jointed; second pair coxhob. 

 with a moveable thumb but no finger. Peduncle of 

 the antennae with two joints. Superior antennae 

 longest. 



Sp. 1. Arliculosa. Body smooth and glossy. Eyes Arliculosa. 

 garnet-coloured. Wrist of the second pair of feet with 

 a projecting compressed lamella. Internal edge of the 

 hand slightly toothed. 



Cancer articulosus of Montagu. 



Leucothoe arliculosa. Leach's MSS. 



Inhabits the bottom of the sea. 



Length half an inch. 



Mus. Montagu, Leach. 



Obs. It is probable that Pkronima sedenlaria of 

 Latreille, Genera Cruslaceorum et Insectorum, vol. i. 

 p. 56. plate 2. fig. 2. forms a distinct family; but as a 

 specimen has never come under our inspection, we shall 

 translate his words in this note. — " Feet ten ; the third 

 pair longest and furnished with compound hands. 



" Cancer sedenfarius Forsk. F. Arab, page 95." 



He observes farther, that it inhabits the Mediterra- 

 nean Sea, dwelling in a cell composed of a gelatinous 

 matter, (perhaps the dead body of a beroe,) of a bladder- 

 like appearance, open at both ends. It often changes 

 its posture, but generally sits within its nest. 



It has lately been discovered in Zetland amongst 

 the rejectamenta of the sea, by the Rev. J. Fleming, 

 one of our most zealous and enlightened naturalists. 



Family XV. Corophini. 



Genus LIX. Corophium. Body elongated, compo- 59. Or». 

 sed of ten joints. Tail three jointed, with four bifid puium. 

 styles. Feet fourteen, the anterior pair furnished with 

 a moveable thumb. The upper antenna; armed with a 

 seta, the under ones as long as the body, very thick, 

 more resembling feet than antennae. 



Sp. 1. Longicornes. The under part of the second Longicwr- 

 joint of the antennae near the apex, armed with a sharp ue »- 

 spine. 



Cancer grossipes of Linne; Oniscus volutator of Pal- 

 las; Gammarus longicornis of Fabricius; Aslacus li- 

 nearis of Pennant; and Corophium longicorne of La- 

 treille. 



Inhabits the European Ocean. 



Length half an inch. 



Family XVI. Caprellini.* 



Genus LX. Caprella. Body linear. Eyes situated eo. Ca- 

 behind the antennae. Antennas four jointed, the upper nm-n. 

 ones with the last segment as long as the three others, 

 and composed of several minute articulations; the un- 

 der ones somewhat compressed, half the length of the 

 superior. The first pair of feet (palpi of Montagu) si- 

 tuated very near the mouth; the second pair with the 

 hand denticulated on the inside. Fins of a membra- 

 naceous jelly-like substance of a globular form. The 

 anus with two little appendices. 



• The body of these animals, exclusive of the head, is composed of six joints, all except the second and third bearing feet. The 

 second and third segments furnished on each side with two processes, which probably serve as fins. Feet ten, all armed with a move- 

 able nail ; the anterior pair very small, and originating from the head. Mouth with two jointed palpi, armed at the point with a little 

 hook. 



The female is furnished with a pouch; situated between the fins, in which she carries about the eggs and her young after their ex- 

 clusion, until they are enabled to shift for themselTes. 



