REPORT ON THE CRUSTACEA MACRURA. 



660 



Second pair five-jointed, long and straight ; basisal joint carrying a small, thread- 

 like ecphysis, and the extremity terminating in two or three spinules and no dactylos. 



First pair of pereiopoda six-jointed ; ischium distally produced at the lower angle 

 and articulating with the meros obliquely ; penultimate joint long, and the terminal one 

 styliform, the dactylos probably being wanting. It supports no branchia, but carries 

 a short, rudimentary mastigobranchial plate. Second pair having the right appendage 

 not very long ; carpos multiarticulate and terminating in a small chela. The mastigo- 

 branchia is a rudimentary curved plate, terminating in a sharp point ; that on the fifth 

 side is wanting. Terminal three pairs of pereiopoda moderately long and robust, 

 carrying a long, slightly curved, style-like dactylos, and furnished on the ischium and 

 meros with sharp, spine-like teeth. 



First pair of pleopoda having the rami unecmal ; the others subecmal and foliaceous. 

 The terminal pair, which helps to form the rhipidura, is subequal in length with the 

 telson ; the outer ramus possesses a diaeresis that is armed with a movable spinule on the 



outer maroin. 



Length, entire, 



„ of carapace, . 



„ of rostrum, . 



„ of pleon, 



„ of third somite of pleon, 



„ of sixth somite of pleon, 



53 mm. (2 in.). 

 13 „ 

 18 „ 

 40 „ 

 10 „ 

 9 „ 



Habitat.— Station 49, May 20, 1873 ; lat. 43° 3' N., long. 63° 39' W.; south of 

 Halifax, Nova Scotia; depth, 85 fathoms; bottom, gravel, stones; bottom temperature, 

 35 c- 0. Two specimens ; male and female. Dredged. 



This species may be identical with Pandalus levigatus, Stimpson, 1 which was dredged 

 off the Island of Grand Manan, Bay of Fundy, on rocky bottoms in the Laminarian 

 zone, but that species is very imperfectly described. Stimpson says that it differs from 

 Pandalus borealis, Kroyer, in the want of dorsal spines on the third and fourth somites 

 of the pleon, and in having only eleven superior spines or serrations on the rostrum, 

 which are situated only on the posterior two-thirds of its length. Its colour is usually a 

 very pale yellow, with narrow blue lines on the back. 



Our type specimen has ten spinules on the dorsal surface of the rostrum, and in this 

 respect it corresponds with the specimen before me, as well as with Leach's figure, of the 

 European type of the genus, Pandalus annulicornis, to which it bears a close affinity. 

 It may be readily distinguished by its long, sickle-shaped dactylos, from which the 

 specific name is chosen. 



The rostrum is produced more horizontally in a line with the dorsal surface of the 



1 Synopsis of the Marine Invertebrata of Grand Manan, p. 58. 



