. Antenna 1, ist-3rd joints subequal or 3rd slightly shorter, 1st about half length of head plus 1st segment. Antenna 2 extending almost as far as apex of 1st joint of antenna 1. Maxilliped, palp rudimentary even in a juvenile of 4 mm., but fully developed in one of 2 mm. Gnathopod 1, 5th joint in <$ ovate with prominent rounded tooth on inner margin; in $ narrow ovate, margin even. Gnathopod 2, 5th joint in S with prominent pointed tooth on inner margin near hinge; in $ inner margin nearly straight, without tooth. Peraeopods 5-7 not very strongly expanded, no ventral point on antero-distal
. Antenna 1, ist-3rd joints subequal or 3rd slightly shorter, 1st about half length of head plus 1st segment. Antenna 2 extending almost as far as apex of 1st joint of antenna 1. Maxilliped, palp rudimentary even in a juvenile of 4 mm., but fully developed in one of 2 mm. Gnathopod 1, 5th joint in <$ ovate with prominent rounded tooth on inner margin; in $ narrow ovate, margin even. Gnathopod 2, 5th joint in S with prominent pointed tooth on inner margin near hinge; in $ inner margin nearly straight, without tooth. Peraeopods 5-7 not very strongly expanded, no ventral point on antero-distal corner of 2nd joint, 3rd joint as broad as 2nd, and only a little less broad than 4th, which has antero-distal corner rounded or at most subacute (not acute) and postero-inferior angle rounded, not prominent, 5th joint narrow ovate. Branchiae single on both segments 3 and 4, rather thick, equal in length to peraeon segments Fig. 173. Paracyamus gracilis (R. de V.). 3-5 together, shorter in ?; accessory appendages a. Dorsal view of $. b. Gnathopod 1 <j. in g short, double on both segments, absent in $. c. Gnathopod I $. d. Gnathopod 2 $. Length: S up to io mm., ? up to 8 mm. e. Gnathopod 2$. /. Branchiae?. Remarks. The above description is based on South African specimens in the South African Museum. This species seems to be always inextricably mixed up with the individuals of Cyamus ovalis. They appear to be confined to the head region of the whale. Genus Isocyamus, Gerv. and Bened. Gervais and Beneden, 1859 (Exp. Meth. Regne Anim., 1), quoted from Stebbing, 1888, p. 316. Gnathopods 1 and 2 unequal. Antenna 2 reduced to three joints. Maxilla 2 without outer lobes. Maxilliped, lobes fused, without trace of palp. Unguis of gnathopod 1 distinct from the dactylus. Branchiae single on both segments 3 and 4. Remarks. Although the characters of this genus were not stated by the original authors, the type, delphini, was designated. The genus may well be resuscitated on the above ch
Size: 1760px × 2840px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectocean, booksubjectscientificexpediti
