52 CRUSTACEA MALACOSTRACA IV. 



46. Platytyphlops orbicularis Calm. 



1905. Platyaspis orbicularis Caiman, Fisheries, Ireland, Sei. Invest., 1904, I, p. 43, PI. V, figs. 77 — 81. 

 11912. Paralamprops Caiman, Proe. U. S. Nat. Mus. vol.41, p. 631, figs. 29 — 39. 



1913. Platytyphlops Stebbing, Das Tierreieh, 39. Lief. p. 158. 



Occurrence. Not taken by the "Ingolf", but by the "Thor" at a single station. 



South-West of the Faeroes: Lat. 6i°7' N., Long, g^o' W., 443 fath. ; 12 specimens, all mutilated, 



most of them fragments. 



Distribution. The species was established on a specimen gathered west of Ireland: 77 miles 

 W.N.W. of Achill Head, co. Mayo, 382 fath. (Caiman). Later it has been recorded from 4 stations situated 

 off the east coast of America, from Lat. 39°54 1 / 2 ' N., Long. 7o°2o' W. to Lat. 39°42' N., Long. 7i°32' W., 

 depths 335—555 fath. (Caiman). 



PlatysympUS Stebbing. 



Of this fine genus only 2 species are known. One among them, P. typicus G. O. Sars, has been taken 

 at the west coast of Norway in some localities from Lofoten to Hardanger Fjord, besides west of Ireland 

 and in the Mediterranean, consequently it might be possible to find it in the southern part of the "Ingolf" 

 area. It has, however, not been discovered there, but I was somewhat surprised in seeing that a couple of 

 specimens of Platysympus taken south of Iceland belong to a new species. 



47, Platysympus tricarinatus n. sp. 



(PI. IV, figs. 3 a— 3 c). 



Immature Specimens (Male and Female). Carapace (fig. 3a) seems to be proportionately a 

 little broader than in P. typicus G. O. S., and with the lateral margins less converging forwards, but as it 

 is cracked in both specimens some uncertainty as to the outline remains. But a valid difference between it 

 and that in the last-named species is that its surface is adorned with three obtuse but distinct keels, one in 

 the median line, and one about halfway between the median keel and the lateral margin; these sublateral 

 keels cease anteriorly near the end of the fissure separating the pseudorostrum ; the surface is a little hollowed 

 along the lateral margins. First free segment differs extremely from that in P. typicus ; it is scarcely half as 

 broad as the carapace, with each antero-lateral corner produced, curved somewhat forwards and acute, 

 while about the posterior half is strongly narrowed, less than half as broad as the anterior part, and the lateral 

 margins of the segment are therefore very concave. Second free segment without distinct keels. 



Antennula?, the three pairs of maxillipeds and second pair of legs differ only in a few minute particu- 

 lars from Sars' figures of P. typicus ; the other cephalothoracic appendages are mutilated. — Uropods (fig. 3 b) 

 nearly as in P. typicus; peduncle slightly shorter than the two posterior abdominal segments together and 

 conspicuously longer than the endopod ; both peduncle and endopod as in P. typicus, but the exopod differs 

 in reaching distinctly beyond the end of second joint of the endopod, while in the other species it does not 



