17 



viser en meget ujevn Overflade, idet saavel Rygskjoldet som 

 Bagkropssegmenterne er tydeligt skulpterede dels med ure- 

 gelmæssige knudrede Fofhøininger, dels med skarpt marke- 

 rede langsgaaende Kjoler, der paa visse Steder hæver sig 

 i Form af hoie, sammentrykte tornformige Fortsatser. 



Nogen tydelig Haarbesætning er kun at se laugs de 

 frie Kanter af Rygskjoldet og Bagkropssegmenterne, medens 

 selve Rygfladen er paa det nærmeste ganske nogen. 



Rygskjoldet (se Fig. 1 og 2). der omtrent indtager 

 1 ; af Totallængden, er oventil stærkt hvælvet og kun i sin 

 allerforreste Del noget nedtrykt. Seet fra Rygsiden (Fig. 1) 

 er det næsten overalt af ens Brede, seet i Profil (Fig. 2) 

 viser det sig derimod fort i 1 betydelig smalere end bagtil, 

 idet de nedre frie Kanter er forti! stærkt opstigende, medens 

 de bag Midten danner en stærk bueformig Bøining nedad. 

 Rygskjoldets Hoide er paa dette Sted neppe mindre end 

 Breden. 



Som ovenfor anført, er Rygskjoldets Overflade meget 

 ujevn. Man bemærker saaledes 3 meget skarpt markerede 

 Længdekjøler, der fra den bagre Rand strækker sig forover, 

 en i Midten og en paa hver Side. Den midterste eller 

 dorsale Kjøl, der er tydelig i hele Rygskjoldets Længde, 

 gaar ud i 3 særdeles store, sammentrykte, fortilkrummede 

 tornformige Fortsatser. alle omtrent af ens Udseende og 

 skilte ved lige Mellemrum. Den bagerste af disse, der ial- 

 mindelighed er lidt mindre end de øvrige 2. staar i kort 

 Afstand fra Rygskjoldets bagre Rand. den forreste noget 

 bag Roden af Pandehoruet. Sidekjolerne er bagtil temmelig 

 lave. men hæver sig foran Midten til 2 lignende, dog noget 

 mindre, skjævt udåd og forti] rettede Torner, hvoraf den 

 bagerste omtrent staar i samme Tværlinie som den midterste 

 af de dorsale Fortsatser. Længere fortil taber disse Side- 

 kjoler sig ganske, og Rygskjoldet viser her et noget for- 

 dybet Parti, der udåd begrændses at en særdeles stor tri- 

 angulært tilspidset og noget skraat udadrettet. horizontal 

 Fortsats, der. naar Rygskjoldet sees ovenfra (Fig. 1) ind- 

 tager dettes forreste Sidehjørner. Disse Fortsatser, der, 

 skjøndt langt mindre udviklede, ogsaa forefindes hos de øvrige 

 Crangonider, synes at svare til de saakaldte Branchiostegal- 

 torner hos andre Macrwrer. Lige nedenunder de omtalte 

 Fortsatser sees et meget lidet tandformigt Fremspring, som 

 er Pterygostomialtornen. 



Pandehoruet viser et fra de øvrige bekjendte Crango- 

 nider temmelig afvigende Udseende. Det er forholdsvis af 

 ikke ubetydelig Størrelse, ved Roden bredt og fladtrykt, 

 men derpaa pludselig stærkt sammentrykt fra Siderne og 

 øxeformigt udvidet, dannende nedentil en i Kanterne tæt 

 børstebesat vertikal Plade. Selve Enden af Pandehoruet 

 er udtrukket i en lang og skarp, skraat opadrettet, lancet- 

 formig Spids. der rækker betydelig udover Iste Par Foleres 

 Basalled, og giver Dyret, seet fra Siden (Fig. 2) et ganske 

 eget Physiognomi, 



Den norske Nordhavsexpedition. Gr. 0. Snrs: Crustace 



exhibit an exceedingly uneven surface, both the carapax 

 and the abdominal segments being distinctly sculptured, 

 partly with rough, irregularly disposed prominences and 

 partly with sharply marked longitudinal carinæ, which, in 

 places. rise as high, compressed, spiniform projections. 



Anv distinct coveriug of hair cannot be detected save 

 along the free margins of the carapax and the abdominal 

 segments, whereas the dorsal surface itself is well-nigh 

 wholly naked. 



The carapax (see figs. 1. 2), which occupies about 

 one-third of the total length, is above exceedingly arcuate, 

 its most anterior portion only being slightly depressed. 

 Viewed from the dorsal side (fig. 1). it appears almost 

 everywhere of equal breadth; seen in profile (fig. 2), on the 

 other hand. it is much narrower anteriorly than posteriorly, 

 the inferior free margins ascending considerably throughout 

 the anterior part. whereas. behind the middle division. they 

 form an exceedingly arcuate descending curvature. The height 

 of the carapax is here about the same as the breadth. 



As stated above. the surface of the carapax is ven 

 uneven. Thus, it exhibits 3 very sharply marked longitudinal 

 carinæ, extending forward from the posterior margin, one 

 in the middle and one on either side. The median or 

 dorsal carina, distinct throughout the whole length of the 

 carapax. rises into 3 exceedingly large, compressed. anter- 

 iorly curved. spiniform processes. all well-nigh uniform in 

 appearance and separated by equal spaces. The hinder- 

 most of these, which, as a rule, is somewhat smaller than 

 the other 2. is placed at a short distance from the posterior 

 margin of the carapax. the most anterior a trifle behind 

 the basis of the rostrum. The lateral carinæ are posteri- 

 orly rather low, but, in front of the middle part. rise as 

 2 similar, but somewhat smaller, spines. pointing obliquely 

 outward aud forward, of which the more posterior about 

 occupies the same transverse line as the median of the 

 dorsal processes. Farther forward these lateral carinæ dis- 

 appear altogether, and the carapax exhibits here a somewhat 

 depressed area. which. exteriorly. is bounded by an extremely 

 large, triangular-acute, horizontal projection, pointing some- 

 what obliquely outward. which, when the carapax is seen 

 ironi above. occupies its antero-lateral angles (fig. 1). These 

 processes. though much less developed, also occur in the other 

 Crangonidians. cor^responding apparently to the so-called 

 branchiostegal spines in the other Macrura. Immediately 

 beneath the aforedescribed processes, is seen an extremely 

 small dentiform projection - - the pterygostomial spine. 



The rostrum exhibits a structural appearance diverging 

 considerably from that in the other known Orangonidæ. 

 In size it is by no means inconsiderable. at the root broad 

 and depressed. but from thence suddenly much compressed 

 laterally and securiform, constituting below a vertical plate, 

 closely beset along the margins with bristles. The extremity 

 of the rostrum is produced into a long and acute, lanceolate, 

 and obliquely upturned point. which projects considerably 

 beyond the basal segment of the Ist pair of antenna?, and 

 gives to the animal — lateral aspect (fig. 2) — a highly charac- 

 teristic appearance. 



3 



