62 



foreliggende Exemplar er vistnok en Han, medens det til 

 Grund for Hellers Beskrivelse af D. spinulosa liggende 

 Exemplar er en Hun; men da det nedenfor beskrevne In- 

 divid aabenbart endnu ikke er slægtsmodent udviklet, er der 

 heller ikke nogen Grund til at antage, at Skulpturen i 

 mærkbar Grad afviger fra samme bos Hunnen. Det er 

 nemlig ifølge mine Undersogelser først efter den Hudskift- 

 ning, der gaar umiddelbart forud for den slægtsmodne Til- 

 stand, at de ofte mærkelige Forandringer i Legemets Form 

 og Skulptur hos Cumacehannerne optræder, der tidligere har 

 givet Anledning til Opstillelsen af flere nominelle saavel 

 Arter som Slægter. Jeg kan derfor heller ikke tvivle om. 

 at de for nærværende Art fra Skulpturen hentede Distinc- 

 tionscliaracterer er af virkelig specifisk Yægt ligeoverfor 

 Hellers Art. 



Beskrivelse. Legemets Form er (se Pl. VII. Fig. 



1 og 2) temmelig undersætsig, med stærkt opsvulmet æg- 

 formig Forkrop og spinkel Bagkrop. Den sidste er. naar 

 Halevedhængene fraregnes, noget kortere end den første. 



Integumenterne er særdeles haarde og stærkt incru- 

 sterede med Kalk. samt, naar afsees fra Lemmerne. næsten 

 ganske nøgne, uden Haar. 



Rygskjoldet er af særdeles betydelig Størrelse, over 

 dobbelt saa langt som de frie Forkropssegmenter tilsammen 

 og ogsaa betydelig bredere end disse, med Gjelleregionerne 

 stærkt opsvulmede. Seet fra Siden (Fig. 2) viser det sig 

 bagtil høit hvælvet eller ligesom puklet, fortil jevnt nedad- 

 skraanende mod det saakaldte Rostrum og her ligesom ind- 

 trykt i Midten. Frontallappen viser (se Fig. 1) den sæd- 

 vanlige, noget klokkedannede Form og har langs ad Midten 

 en utydelig Kjøl. Det loran samme fremskydende. af de 



2 i Midtlinien sammenstodende Sidefliger dannede Frem- 

 spring, der kun høist uegentligt kan benævnes Pandeborn 

 eller Rostrum. indtager omtrent x / 5 af Rygskjoldets Længde 

 og er koniskt tilspidset samt horizontalt. med Sidekanterne 

 grovt tandede. Nedenunder det saakaldte Pandeborn danner 

 de frie nedre Kanter af Rygskjoldet (se Fig. 2) et stumpt 

 tandet Hjørne og har længere bagtil et stærkt bugtet For- 

 løb, med en stærk Boining omtrent paa Midten. 



Rygskjoldets Overflade viser overalt en meget iøine- 

 faldende Skulptur i Form af talrige smaa Gruber, der giver 

 den et elegant spættet Udseende. Desforuden bemærkes 

 nærmere den dorsale Flade et Antal af symetriske gruppe- 

 rede større knudeformige Fremspring, der er af stumpt til- 

 rundet Form og ligesom polerede. Man tæller ialt omtrent 

 32 saadanne. bvoraf dog nogle er mindre tydelige. Mest 

 iøinefaldende er til hver Side 8 større Knuder. der danner 

 en nogenlunde regelmæssig horizontal og noget buet Række 

 strækkende sig fra det saakaldte Pandeborn og bagover 

 indtil det mest ophøiede Parti af Rygskjoldet. Begge disse 

 Knuderækker begrændser tilsammen et noget fordybet ovalt 

 Felt. der forstørstedelen repræsenterer den saakaldte Mave- 

 region; bagenfor dette staar desuden til liver Side 2 lige- 

 ledes tydeligt markerede Knuder. dannende sammen en re- 

 gulær Firkant (se Fig. 1). 



are furnished. The only example secured is. indeed. a male. 

 whereas the specimen from which Heller worked out his 

 description of D. spimdosa, is a female; but the specimen 

 described below being nut yet sexually developed. there is 

 no reason to infer that tlie sculpture should in any perceptible 

 degree deviate from that in the female. According to my 

 researches, it is not till after the moult. which imme- 

 diately precedes the sexually mature state, that the changes, 

 frequently so remarkable, in the form and sculpture of the 

 body characterising the males in' Cumacea actually occur, 

 — a circumstance that has previously led to the estab- 

 lishment of several spurious species and genera. Hence. 

 I am fully convinced. that. to the distinctive characters 

 educed for the present species from its sculpture we can attach 

 a real specitic weight when comparing it with Heller's species. 



Description. — The form of the body (see Pl. VII. 

 figs. 1. 2) comparatively thickset, with the cephalo-thorax 

 considerably swollen and ovate, and the abdomen slender. 

 Excluding the caudal appendages. the latter is somewhat 

 shorter than the former. 



The integuments are exceedingly hard and strongly 

 incrusted with lime, as also, apart from the limbs. almost 

 entirely naked. and without hair. 



The carapax is of very considerable size. more than 

 twice as long as the free segments of the cephalo-thorax 

 tåken together. and also considerably broader. with tite 

 branchial regions much swollen. Viewed from the side (fig. 

 2 1, it appears. posteriorly. high and arcuate. or. as it were, 

 liunclied. anteriorly shelving down toward the so-called 

 rostrum. and there impressed in the middle. The frontal 

 lobe exhibits (see fig. 1) the usual, somewhat hell-shaped 

 form. and has. extending along the middle. an indistinct 

 carina. The process generally termed the rostrum. jut- 

 ting out before the lobe, aud composed of the lateral 

 lobules that meet on the medial line. measures about one- 

 fifth "f the length of the carapax; it is conically pointed 

 and horizontal. with the lateral margins coarsely dentate. 

 Underneath this rostriform projection. the free margins of 

 the carapax (see fig. 2) form an obtusely dentate corner, 

 and somewhat farther behind are exceedingly sinuous. with 

 a strong curve about in tlie middle. 



The surface of the carapax exhibits everywhere a very 

 conspicuous sculpture. with numerous small pits. giving it :i 

 curious speckled appearance. Moreover. in close proximity 

 to the dorsal surface are seen a number of large, sym- 

 metrically disposed, tuberculiform projections, obtusely rounded 

 in form, and. as it were. polished. In all. may be counted 

 32 such projections, some of which however are less dis- 

 tinctly developed. The most conspicuous are 8 large protu- 

 berances. on either side, constituting a comparatively regular 

 horizontal and somewhat arched series, extending posteriorly 

 from the so-called rostrum to the most elevated portion of 

 the carapax. Both of tliese series of protuberances constitute 

 together the boundary of a somewhat depressed oval area, 

 representing the greater part of the so-called gastric region : 

 posterior to this area occur. moreover, on either side. 2 distinctly 

 marked protubei'ances, that form a regular square (see fig. 1). 



