39* 



CRUSTACEOLOGY. 



GtuSfaeta. Deep in the wat'ry vast the comrades rove, 



'■ «» y '*m* And mutual interest binds their constant love; 



That wiser friend the lucky juncture tells, 

 When in the gaping circuit of hill shells 

 Fish wandering enter ; then the bearded guide 

 Warns the dull mate, and pricks his tender side ; 

 lie knows the hint, nor at the treatment grieves, 

 But hugs th' advantage, and the pain forgives ; 

 His closing shells the pinna sudden joins, 

 And twixt the pressing sides the prey confines. 

 Thus fed by mutual aid, the friendly pair 

 Divide their gains, and all the plunder share. 



Pisuro. Sp. 1. Pisum. Shell orbicular, of a reddish colour; 



hands oblong. 

 Platb Inhabits various species of mussels. In one hundred 



GCXXI. of Mytilus modiolus, Mr Leach found three of this 

 rig. 3. species. Male unknown. See Plate CCXXI. Fig. 3. 

 Varians. &P- 2. Varians. Shell of an oval-round, somewhat 



narrow in front, very convex, solid and marbled; hands 

 oval ; fingers arched. Female unknown. 



Pinnothere des monies. Latreille Hist. Nat. des Crust. 



el des Ins. torn. vi. p. 83. pi. 48. 

 (lancer varians. Oliv. Encycl. Mclk. Hist. Nat. t. vi. 



p. 155. 

 Pinnotheres mytilorum. Latr. Gen. Crust, et Ins. vol. i. 



p. 35. 

 It is highly probable that Cancer pinnophylax and 

 Pinnotheres of Linne belong to this genus. They are 

 \mknown to all the naturalists of the present time. See 

 Pinnotheres mylili, modioli, pinnae, pisum, varians, and 

 mytilorum in the Index, as we have obtained some 

 interesting facts lately, respecting the genus and its 

 species. 



* All the feet rviih conic tarsi. 



Family VIII. Oxyrhynchi. 



Observation. It is very evident that Cancer rhom- 

 ttoidalis of Montagu (Lrnnean Transactions, vol. vii. 

 tab. 6. p. 84. ) belongs to this family, but is not referable 

 to any genus hitherto established ; and as a specimen of 

 it has never come under our inspection, we shall de- 

 Scribe it in his own words. 



" Cancer rhomboidalis : with an uneven rough thorax, 

 destitute of spines, but furnished with three large tu- 

 bercles on the fore part, and two others near the tail : 

 front, a broad thin concave plate, projecting into a long 

 sharp-pointed proboscis: antennas two^setaceous, longer 

 than the proboscis : eyes vastly large, prominent, reti- 

 eulated, pedunculated, nearly half the diameter of the 

 thorax ; arms large in proportion, smooth ; on the first 

 joint beneath, a hooked spine turning upwards ; fangs 

 toothed ; legs eight, subulate, _a long spine on the first 

 joint of each, underneath; tail nearly as long as the 

 body, slender, cylindric-clepressed, formed with five 

 joints ; the end truncated, hirsute : colour, when alive, 

 light olive-green. Length from the point of the pro- 

 boscis to the end of the tail, a quarter of an inch. Found 

 amongst sertulariaz or the back of Cancer dodecos." 

 am lsm . Genus XXIII. Leucosia. Shell somewhat oval and 



•osj*. convex. (The greater part in most of the species 



smooth.) The double external palpi with equal narrow 

 footstalks; the second joint narrowing towards the point, 

 and reaching the anterior margin of the shell. Antennae 

 and eyes minute. 

 Nucleus. Sp.l. Nucleus. The clypeus with two teeth-like pro- 



cesses in front : the posterior margin of the shell with 

 two folds and a minute spine on the upper side ; arms 

 •f an equal siae and elongated. 



Inhabits the Mediterranean Sea. Crustacea. 



Cancer nvcleus of Linne ; Leucosia nucleus of Fabri- w "Y"*"~ ' 

 cius and Latreille. 



Sp. 2. Craniolaris. Shell granulated ; anterior part de- Craniolaris. 

 pressed above, posterior margin wrinkled, without 

 spines ; one tooth-like process in the middle of the cly- 

 peus; arms warty beneath ; hands cylindrical and com- 

 pressed ; fingers conical, the internal side with sharp 

 teeth. 



Inhabits the shores of Malabar. 



Cancer craniolaris of Linne ; Leucosia craniolaris of 

 Fabricius and Latreille. 



Genus XXIV. Maia. Shell nearly triangular, (gene- 24. Maia. 

 rally rough and rostrated in front.) The internal foot- 

 stalk of the external double palpi with two broad joints. 

 Space between the eyes very wide. Feet nearly equal 

 in size and shape : the hinder feet being neither small nor 

 spurious. See Ilyas Inachus, in the Index. 



Division I. Arms very thick, and extending in a right 

 angle. 



Sp. 1 . Horrida. Shell spinous, the upper surface very Horrida^ 

 unequal and irregular: tail as if worm eaten; hand oval. 

 Inhabits the Asiatic Ocean. 



Cancer horridus of Linne ; Parthenopc horrida of Fa- 

 bricius ; Maia horrida of Latreille. 



It is described by Petiver under the name of the 

 great warty crab; is the Rotskrabbe of Rumphius, the 

 Die schreck/iche of Herbst. 



For Cancer horridus of Pennant, see Lilhodes maja, 

 Genus 26. 



Sp. 2. Giraffa. Shell spiny, with the spines branch- Giraffe 

 ed : hind claws very long and tuberculated beneath. 

 Inhabits the East Indies. 

 Cancer giraff of Fabricius. 



Sp. 3. Muricata. Shell unequal and hairy, with a Murica** 

 double line and two dorsal spines on each side ; margi- 

 nal spines four ; legs hairy. 

 Habitat unknown. 



Cancer muricatus of Fabricius. Enl. Syst. 

 Division II. Arms extended forwards, and not re- 

 markably thick. 



* Second pair of feet neither three times the length 

 of the body, nor very slender. 



Sp. 4. Araneus. Thorax rough and tuberculated ; Araneus. 

 rostrum bifid; claws oval. 



Inhabits the European seas, frequenting all our sandy 

 coasts, particularly the mouths of rivers, where it re- 

 sides in deep water, and is taken by the oyster dredgers, 

 who name it harper or spider crab; and, as they supr 

 pose it injurious to the beds, always bring it ashore and 

 destroy it. It is very frequently covered with bernaclesy 

 alcyonia, sponges, fuei, and other marine substances. 

 Its common size is about ten inches across from the tip 

 of one arm to the other, bvit it sometimes measures 

 sixteen from these points. The arms of the male are 

 considerably longer than those of the female. It spawns 

 during the greater part of the year. 

 Cancer araneus of Linne and Pennant. 



Sp. 5. Armala. Shell of an elongated triangular Armasa* 

 form, hairy, with three dents behind ; clypeus with two 

 strong spines ; hands elongated. 



Maia armata of Latreille. Inachus opilio of Fabricius-. 

 Inhabits the Mediterranean Sea. 



Sp. 6. Squinado. Shell rough ; the front with two Squinagc. 

 spines, the sides with six elongated conic spiny pro- 

 cesses: the arms scarcely longer than the following pair 

 of feet ; hands cylindrical and smooth ; fingers tuber- 



6Vlb$.Q'X 



