Discussion

I have been able to obtain the original description of only one of the doubtful species listed by Stebbing (1906: 643), that of P. dubius which is given by Stebbing (1888: 167) in a resume of Templeton's original paper (1836). Stebbing makes it clear that P. dubius does not agree with my specimens—e.g., it differs in having a minute accessory flagellum which Templeton described but did not figure. Papers describing P. validus (Czern.) and P. virescens (Stimpson) are not available. P. ferox Chevreux, described and figured by Chevreux and Fage (1925: 336, figs. 345), differs very obviously in the gnathopods, the male 2nd gnathopod having the palm defined by a large tooth, and in the telson which is “arrondi, avec 2 paires de soies submarginales et 2 petites épines crochues”. In most features, especially the telson, P. lessoniae comes close to P. gammaroides, but from Sars' figures (1895: plate 207) it is evident that there are differences in the 1st maxilla palp which has the 2nd segment exceedingly long in P. gammaroides; in the lower lip which has the outer distal angle very strongly produced distally; and in the 6th segment of peraeopods 3–5, which has a very distinct spine on the palm near the base of the dactylos in P. gammaroides. As well, both P. ferox and P. gammaroides possess eyes; P. lessoniae appears to have none. Accordingly, I am describing these specimens as a new species, distinguished particularly by the nature of the 1st maxilla palp, the telson, the 6th segment of peraeopods 3–5, and the absence of eyes.