Die nordischen Schizopoden. VI 117 



Bestimmungsschlüssel der nordischen Arten. 



1. Das Telson ist halb so lang wie das 6. Abdominalsegment: D. sarsi Ohlin. 

 Das Telson übertrifft das halbe 6. Abdominaisegment an Länge: 2 



2. Der zweite Antennenstamm hat außen am Basalglied einen langen spitzen Dorn: 



D. goniops. 

 Der zweite Antennenstamm hat keinen solchen langen spitzen Dorn: 



D. thaumatops. 



70. Dactylamblyops thaumatops Tattersall. 



1907. Dactylamblyops thaumatops Tattersall, Ann. nat. hist. ser. 7 v. 19, 



p. 113, 114. 



„Carapace covering all the thoracic segments except the last; produced in 

 front into a short, broadly rounded, obtuse rostrum, which extends to the distal 

 end of the first Joint of the antennular peduncle and partially Covers the eye-stalks; 

 evenly rounded at the antero-lateral corners and emarginate behind; cervical 

 sulcus well marked. 



Pleon longer than the carapace; the first segment a little longer than the 

 second, which is subequal to the third, fourth, and fifth; sixth segment twice as 

 long as the fifth. 



Eyes small, extending forwards to the distal end of the second Joint of the 

 antennular peduncle; pyriform in shape, with distinct eye-stalks; each eye with a 

 Short digitiforni process on the inner and upperface; a broad membranous ledge 

 projecting at right angles to the surface of the Cornea Starts at the outer lateral 

 part of the eye-stalk and runs equatorially round the outer part of the eye, 

 terminating just ventral to the digitiform process and dividing the Cornea into a 

 dorsal and ventral portion; the ledge is broadest about the centre of the Cornea 

 and narrows off at either end; visual Clements imperfectly developed, numerous, 

 reaching to the surface of the eye; pigment pale purplish pink. 



Antennular peduncle about twice as long as the eye and three quarters of 

 the length of the antennal scale; third Joint slightly longer than the first; second 

 Joint small. 



Antennal peduncle about half as long as the scale; the three joints roughly 

 subequal in length. 



Antennal scale about one third as long again as the antennular peduncle 

 and twice as long as the antennal; about four times as long as broad; outer 

 margin entire and terminating in a spine, beyond which the apex of the scale is 

 not produced; spine on the outer distal corner of the basal Joint obsolete. 



Mouth-parts and first and second thoracic limbs not differing in any striking 

 way from those of the type species. 



Remaining thoracic limbs missing. 



