Prbto peddtus. 



673 



tab. 101. fig. 1, 2. — Cancer Gammarus pedatus Montagu^ in 

 Lin. Trans., xi. 6. pi. 2. fig. 6. — Leptomere pediare Desm,, 

 Crust., tab. 46. fig. 3. [In our p. 672., last line, for "376." 

 read " 276."] 



Hab. — South coast of Devonshire, Montagu ; at the Bell Rock, Rev. 

 Dr. Fleming; Berwick Bay. 



Body slender, arched, pellucid white with a few reddish specks, smooth 

 and naked. Head obtuse in front, contracted into a neck behind ; the 

 eyes roundish and of a red colour: superior antennae about half the length 



Prbto pedatus, var. 1. 



of the body, the terminal joint hispid with short ciliae at the junctures; the 

 inferior antennae slenderer, considerably shorter, and almost naked. First 

 pair of hands small ; the second greatly larger, oval, with a denticle or two 

 near the base ; and each armed with a powerful claw, closing along the 

 inner side; the wrist joints small, the humeral linear-elongate. Third and 

 fourth pairs of legs very slender, filiform ; the femoral joint elongate, 

 slightly clavate ; the other joints shortened outwards ; the claw long; fifth 

 pair equally slender and much shorter : the sixth and seventh pairs con- 

 siderably stouter, longer, and nearly equal, with an elongate femur, the 

 knee very small, the tibia as long as the femur, the two tarsal joints shorter 

 and sparingly hispid : the sixth pair arise from the hinder end of the sixth 

 segment, but the seventh pair is terminal ; and just before the origins of 

 the latter there are four minute styles curved backwards and attached to 

 two converging lamellae. 



In the female, the ova are produced in a pouch formed by converging 

 scales under the third and fourth segments, counting the head as the first. 

 At first the pouches are distinct, and appear in the form of a globular pro- 

 tuberance between the legs ; but at last they coalesce, and form one great 

 uterine cavity, which opens about the middle when the ova or young are 

 ready for birth. Montagu could not discover any styles under the ter- 

 minal segment, and is of opinion that these constitute a sexual character. 

 They were easily detected in the several specimens which I have had the 

 opportunity of examining, some of which had no protuberances at the 

 branchial lamellae, and appeared in consequence to be males ; but I sus- 

 pect the animal can conceal these styles at will, and cover them with 

 lamellae, in the same way as the Astacilla and Idoteaidae do their caudal 

 appendages. 



I have considered our specimens as referable to the species delineated 

 and described by Miiller and Montagu, although there are some differences 



Vol. VIII. — No. 56. 3 b 



