_58_ 



on the transversely truncated end of the endopodal part. Anterior maxillipeds 

 with the terminal part very short, uniarticulate. Posterior maxillipeds forming 

 each an oval undivided lamella clothed inside and at the tip with a number 

 of thiekish plumose setae. 1st pair of legs with the rami of about equal size, 

 the outer one exhibiting only very slight traces of spines outside, its terminal 

 joint of a somewhat irregular shape, being expanded, inside the insertions of 

 the setae, to a rounded lobe edged with 3 short denticles. The 3 succeeding 

 pairs of legs much longer than the 1st, and of a very different structure, being 

 apparently quite immobile, as only very slight traces of muscular bands are 

 detected within them ; outer ramus considerably produced and conically tapered, 

 inner one extremely small, being composed of a short basal joint folloved by 

 a narrow, peculiarly twisted terminal piece, which in the 4th pair is simple, but 

 in the 2 preceding pairs divided by 2 successive circular crests as it were in 

 3 joinis. Of a 5th pair of legs not the slightest trace could be detected in 

 the specimens examined. 



Body in the living animal of a pale yellowish grey colour, with a 

 slight bluish tinge; ovarial tubes and ripe ova of a somewhat darker 

 violaceous hue. 



Length of adult female attaining nearly 5 mm. 



Male unknown. 



Remarks. The present form is easily recognisable from any of the other 

 Doropygidae, both as regards its outward appearance and the structure of the 

 several appendages. The large size of the Norwegian specimens is very 

 remarkable, and could led to the suggestion that they belonged to a 

 species different from that observed in the Mediterranean and on the 

 French coast. 1 ) As however no other reliable difference could be detected 

 to distinguish the Norwegian form, I have not felt justified to separate it 

 specifically. The Sphceronotus Thorelli of Glaus is evidently identical with 

 Costa's species. 



Occurrence. Some few female specimens of this remarkable form were 

 obtained, many years ago, from large specimens of Phallusia mentula taken 

 in the upper part of the Trondhjem Fjord. 



Distribution. Mediterranean (Costa), coast of France (Canu), coast of 

 Bohuslan (Aurivillius). 



*) Canu gives the length of the body to only 2.50 mm. 



