(i6 



13. Sphyrapus serratus. Gr. 0. Sms. u. sp. 



(Pl. XXI. 



Sphumptis serratus, «i. 0. Sårs, Etevision ai' Gruppen [sopoda chelifera, 

 pg. 20. 



Artscharaeteristik. Legemet hos Hunnen neppe 5 

 Gange saa langt som bredt, hos Hannen betydelig sniækrere. 

 Pandepladen meget bred, horizontal, i Midten uddraget i 

 m stump 4-tandet Spids. Sidste Forkropssegment betydehg 

 kortere end de ovrige. Bagkroppeus 5 første Segmenter 

 med udstaaende, triangulært tilspidsede Epimerer. Sidste 

 Segment stumpt tilrundet. Ingen Øine. Iste Par Føleres 

 Basalled meget stort, udvidet paa Midten, med 4 Børster 

 i den ydre Kant; den indre Svøbe ganske kort, o-leddet, 

 den ydre hos Hunnen 5-leddet. hos Hannen 7-leddet. Sax- 

 fødderne kraftigt udviklede. med stærkt opsvulmet Haand, 

 Tibialleddet hos Hannen længere end Tarsalleddet. Grave- 

 tt iddernes næstsidste Led hos Hunnen bevæbnet med 3 

 stakke Torner i den indre Kant. Halevedhamgene neppe 

 hengere end Bagkroppen, med den ydre Gren meget liden 

 og 3-leddet. den indre 10-leddet. Farven ensformig hvid. 

 La-ngden 5 — -6""". 



Findesteder. Stat. 40, 51, 353. 



Bemærkninger. Nærværende Art viser en saa paa- 

 faldende Lighed med den af mig tidligere characteriserede 

 norske Art. Sph. anomalus. at jeg i lang Tid kun holdt 

 den for en Varietet af samme. Ved den noiere anatomiske 

 Undersøgelse. jeg senere har anstillet over begge disse 

 Former, har jeg dog fundet visse constante Forskjelligheder 

 saavel hos Hun som hos Han, der gjør det nødvendigt at 

 skille dem som distincte Arter. Et meget let opfatteligt 

 ydre Kjendemærke for nærværende Art er de til Siderne 

 stærkt udstaaende og triangulært tilspidsede Epimerer paa 

 Bagkroppens 5 forste Segmenter, hvilket har givet Anled- 

 ning til Artsbenævnelsen. Hos Sph. anomalus er disse Seg- 

 menter til Siderne stumpt afrundede, og hele Bagkroppen 

 synes derved ogsaa her betydelig smalere. 



Beskrivelse af Hunnen. Legemet er (se Pl. XXI, 

 Fig. 1 og 2) noget nedtrykt og jevnt afsmalnende bagtil, 

 med den største Brede, der falder over Iste frie Forkrops- 

 segment, noget større end 1 / 5 af Længden. 



Integumenterne er temmelig liaarde. glatte og glind- 

 sende, samt uden nogen bemærkelig Haarbesætning, naar 

 afsees fra Lemmerne. 



I )et forreste Kropssegment, der kun uegentlig kan be- 

 oævnes Hovedet, da det i sig tillige indbefatter det Iste 

 fodbærende Segment, er meget stort, dannende et Slags 

 Rygskjold (carapax) af triangulær Form, med den største 

 Brede, der omtrent er lig Længden, i sin bagerste Del. 

 Kortil gaar det ud i en bred. horizontal Pandeplade. der i 

 Enden er udtrukket i en kort stump Spids besat med 4 

 sniaa Tænder (se Fig. 4). Ved Basis af denne Pandeplade 

 og indtagende Sidehjørnerne af Hovedskjoldet sees 2 smaa 



13. Sphyrapus serratus. G. (). Sårs. n. sp. 



(Pl. XXI). 



Sphyrapus serratus, <i. I >. Sårs. Revision af Gruppen Isopoda chelifera. 

 p. 20. 



Specifie Charaeter. — Body in female scarcely 5 

 times as long as broad, in male much more slender. 

 Frontal plate exceedingly broad. horizontal. produced in 

 the niiddle to an obtuse four-toothed point. Last thoracic 

 segment considerably shorter than the others. Five first 

 segments of abdomen with projeeting. triangular. acuminate 

 epimera. Last segment obtusely rounded. No eyes. Bas;il 

 joint of Ist pair of antenna' exceedingly large, dilated in 

 the middle. with 4 bristles on the outer margin: inner 

 nagellum very short. three-jointed: outer in female tive- 

 jointed, in male seven-jointed. Chelipeds powerfully de- 

 veloped, with the hand greatly swollen; tibial joint in male 

 longer than tarsal joint. Penultimate joint of fossorial legs 

 in female armed with 3 strong spines on the inner margin. 

 Caudal appendages scarcely. if at all. longer than posterior 

 division of body. with the outer branch exceedingly small 

 and three-jointed. the inner ten-jointed. Colour a uniform 

 white. Length from 5 to 6""". 



Loeality. — Stats. 40. 51. 353. 



Remarks. — The present species exhibits so striking 

 a resemblance to the Norwegian I had previously described 

 under the name of Sph. anomalus, that I long held it 

 to be a mere variety of that form. Meanwhile. a closer 

 anatomical examination of both these animals has brought 

 to light divers constant deviations both in the female and 

 the male. that render it necessary to establish them as 

 distinct species. A readily appreciable outer characteristic 

 in the present form are the triangularly pointed epimera 

 on the 5 first segments of the abdomen. prominently pro- 

 jeeting toward either side. from which indeed the sjiecitic 

 designation is derived. In Sph. anomalus, these segments 

 are at the sides obtusely rounded: and hence the whole 

 posterior division of the body in that species too. appears 

 considerably more slender than in the present form. 



Deseription of the Female. — The body somewhat 

 depressed (see Pl. XXI, rigs. 1. 2) and tapering gradually 

 backward. with its greatest breadth. that occurs across the 

 Ist free thoracic segment, slightly exeeeding one-fifth of the 

 length. 



The integuments comparatively hard. smooth. and 

 lustrous, as also without any covering of hair. except on 

 the appendages. 



The most anterior segment ot the body, which in 

 anvtliing but a strict sense can be termed the head. com- 

 prising as it does also the Ist pedigerous segment, is ex- 

 ceedingly large, constituting a kind of carapax. triangular 

 in form. its greatest breadth about equal to the length across 

 the posterior portion. Anteriorly. it projects as a broad. 

 horizontally extending frontal plate, which. at the extremity. 

 is produced to a short. obtuse point, beset with 4 small 

 teeth (see fig. 4). At the base of this frontal plate, and 



