Title: Notes on the crayfishes in the United States National museum and the Museum of comparative zoölogy : with descriptions of new species and subspecies, to which is appended a catalogue of the known species and subspecies / by Walter Faxon
Abstract:branchial formula is the same as in the genus Cheraps, and essentially the same as in Paranephrops ; but according to Nobili the podobranchiae of the eighth and ninth somites are not furnished with an...branchial formula is the same as in the genus Cheraps, and essentially the same as in Paranephrops ; but according to Nobili the podobranchiae of the eighth and ninth somites are not furnished with an ala or lamina in the genus Astacone- phrops, whereas in the genus Cheraps these podobranchiae are alate.Parastacus araucanius, sp.nov.Plate 4.Male: -Cephalothorax shorter than the abdomen, strongly compressed laterally, mostly smooth, minutely granulated on the sides; areola broad (about two thirds as broad as long), minutely punctated; rostrum short, not reaching the distal end of the second antennulary segment, margins elevated, slightly convergent from base to near the tip, where they abruptly converge to form the abbreviated acumen; the infero-lateral edges of the rostrum are %'isible from above, forming the superior border of the orbit separated from the supero-lateral edge of the rostrum by a groove; distal half of the rostrum concave above;antero-lateral margins of the carapace produced into a prominent, rounded angle below the small eye which lies in a deep and uncommonly complete orbit.Post-orbital ridges, obsolete.The pleural angles of the abdomen are rounded, the telson long with a pair of lateral spines and a longitudinal median furrow on its upper face along its distal half; the mecUan rib on the upper side of the inner branch of the last pair of abdominal appendages ends in a small spine situate a little distance from the margin.Antcnnal scale short and broad.The chelipeds are asymmetrical, the right one being the larger; the meros is tuberculated on its lower face, granulate on the superior margin, but destitute of spines ; the surface of the carpus is lightly squamoso-granulate, the granulations becoming more pronounced on the supero-interior edge where they take the form of blunt tubercles; the chela, too, is lightly squamoso-granulate, without any prominent spine or tubercle, except one ]:)lunt tubercle or tooth near the base of the immovable finger; the superior and inferior borders are rounded.Dimensions.Length, 42 mm.Read More