2Q LAMELLIBRANCHIATA. 



e. o^. 6, 8 (PI. I, figs. 5a & b), 10 and 12. Sometimes the intermediate ribs are almost as well developed as 

 the primary, so that the difference is not appreciable, and the sculptnre then assumes a certain res- 

 emblance to that in Pecten islandicus; it lacks however the characteristic intercostal, rasp-like structure 

 of the latter (PI. I, figs. 5 c & d). Each primary rib again is composed of a varying number of small 

 ribs, which may be smooth but are usually rough (at least towards the periphery) from the presence 

 of small, erect scales (PL i, fig. 5e). All the specimens to hand are grayish-yellow to straw- or orange- 

 yellow (elsewhere the colour is described as purple-red or rose-red). The largest specimens measured: 



Length Height Breadth 



29.5™™ OQ mm jr' 



29.5 - 29.5 - 8 



28.5 - 29 - 7 



24.5 - 27 - 7 



■ mm 



Distribution. Pecten aratits ranges from Morea through the Mediterranean to the Atlantic 

 off Soudan ("Talisman"), Pyrenean Peninsula, France and Ireland, as also north of vShetland'); further, 

 it occurs from Bohuslan along the coast of Norway to Lofoten ^). Lastly, the Danish investigations 

 have shown that it goes south of the P"seroes and south of Iceland and a good way up into the 

 Denmark Strait. Its vertical distribution is placed by Jeffreys at from 20 to 530 fm.; the "Ingolf" 

 however has taken a living (though small) specimen at a depth of even 788 fm. (St. 10). 



Among the synonyms of this species Jeffreys gives Pecten briiei Payraudeau, but French 

 and Italian authors do not agree with him here. After examining a specimen of P. brnei (from 

 Corsica) sent to our Zoological Museum by ^larchese di Monterosato, I consider there is no doubt, 

 that Jeffreys is right; this means at the same time that P.aratus is distributed in the Mediterranean. 



Pecten septemradiatus Miiller. 

 PI. I, figs. 6a — -c [\2iX. scaber). 



Ostrea septemradiata Miiller, Zool. Dan. Prodr., 1776, p. 248. — Pecten septemradiatus Jeffreys, Brit. 



Conchol. II, 1863, p. 62, PI. 23, fig. i. 



This species has been taken by the "Ingolf" at the following stations: 



W. of Iceland 138 fm. 5.9" C. Fragments of numerous valves. 



St. 98. 



- 89, 



- 9 



- 8. 



- 85. 



- 55' 



- 6. 



S.W. 



S. E. - - 



N. W. of the Faeroes i ?2 - 



■) During mj- participation in the cruise of the "Michael Sars'' in 1902, I obtained a specimen at 6o°2:.5' N. L-, 3° 

 55'W.L., 148 fm. 



2) Neman's record of its occurrence right up at 71° i2'3o" N.L., 20°3o'3o" E.L., 135 fm. seems hardly credible and 

 is based in all probabihty on an erroneous determination (Niederland. Arch. f. Zoologie, Suppl. Bd. i, 1S81 — 83, No. 10 p. 3). 



