May, 1909 The hish Naturalist lor 



vSPINTHER ONISCOIDES, JOHNSTON. 



BY W. RIDDELL, :\r.A. 



(pirate I.) 



The genus Spinther was esLablished by Johnston (5) in 1S45, 

 for an annelid dredged in Belfast Lough. Unfortunately the 

 type-specimen has disappeared. In 1850 Sars (co) described, 

 under the name of Oniscosoma ardiaim^ an annelid from 

 Komagfjord, parasitic on a sponge. In 1S54 Stimpson (11) 

 described a similar form from the Bav of Fundv, callins: it 

 Cryptonota citrina. In i85o Grube (3) described a new species 

 of Spinther, S. miniaceiis, from Trieste. In 1865 Claparede 

 (i) pointed out the identity of the genera Spinther, Oniscosoma, 

 and Crj'ptonota ; and Malmgren (7), in 1867, included Sars' 

 species under the genus Spinther. M'Intosli (8), in 1865, 

 described from North Uist a form which he at first regarded 

 as kS. oniscoides Johnst , but afterwards (9) identified as S. 

 miniaceiis Grube. 



In 1882 Hansen (4) described a form which he identified as 

 S. arciicus Sars, but which v. Graff (2) has shown to come 

 nearer 5. oniscoides. Wiren (13), in \^%z^ ^^so described a \ 



species which he called S. arcticics, and identified with Hansen's 

 form, but which, as he himself noted, differed in many respects 

 from vSars' form. 



In the same 3"ear Levinsen (6) gave a diagnosis of the genus, 

 and included two species — S. arctinis, wiiich included both 

 Sars' form and Wiren's, and S. major, n. sp., for Hansen's 

 vS. arcticns. 



In 1887 von Graff (2; published a paper — " Der Anneliden- 

 Gattung Spinther " — in which he gave a complete history of 

 the genus, described fully the anatomy, and distinguished 

 three species. These species were — (i) 6". 07iiscoides Johnston, 

 = Ciyptonota citrina Stimpson = 6*. aixticus Hansen = S. 

 major Levinsen ; (2) 6". viiniaccus Grube = O?iiscosoma arcti- 

 cnm Sars = 5. arcticns Sars, Malmgren, and Levinsen ; (3) ^, 

 aj'cticus Wiren. This last species he identified with 



M'Intosh's 6*. 07iiscoides (1865), which M'Intosh has since 

 shown to belong to the species vn7iiaceus^ 



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