KONGL. SV. VKT. AKADEMIENS HANDLINGAR. BAND. 22. N:() 7. 253 



The reasons why I here take Parathemisto ahyssorum, A. Boeck, as a synonym for 

 Hyferia ohllvia, H. Kroeyek, are that the few chai*acteristics given by Khoeyek exactly 

 agree with tliose of Parathemisto ahyssorum, and tha.t Boeck never was ;iAViU'c of the, fact 

 that Hyperia, oblivia belonged to the new genus Parathemisto, and so in 1872 ho gavc Hyperia 

 ohllvia as a synonym för H. medusarum and thus did nothing to clear iip the question. 



The diagnosis of the species given by Kroeyek in 1838 runs: 



nHij]]e7ia ohlivia: antennis superioribus brevioribus, validis, uncinatis, setosis; antennis in- 

 ferioribus gracilibus, flagello scapum longitudine ter superante; pedibus secundi paris graciHbus, 

 inai-gine tertii et qvarti articuH posteriore infra iu stylum producto, imgue non infiexo; pedibus 

 tertii qvartique paris, ut duo paria priora longitudine superantibus, ita a paribus seqventibus, 

 qvfe invicem ejusdem fere sunt longitudinis, superatis. Qvinqve paria ultima formain uoruni 

 parium in Metoeco Me.dusarum prorsus imitantur.» 



From his description I translate the passages respecting tlie Urst two pairs of peraeo- 

 poda, the rest of the description being of but little importance for the identiiication of 

 the species. 



»The first pair of legs are small but robust: the first joint is the longest and is tolerably 

 thick; the second and third joints are very short, and so closely united, that it is difficult to see the 

 line of junction between theni; the fourth joint is longer than the two preceding together, and is very 

 thick; the fifth joint is about as long as the fourth, somewhat more slender, and a little narrowed 

 at the apex; the sixth joint is a tolerably long and acute claw, which is not much curved. Some 

 long, ;,very slender and soft hairs are to be seen at the hind corner of the under margins of the 

 first three joints, along the hind margin of the fourth joint, and on both the front and hind 

 margins of the fifth joint. 



The second pair of legs are longer than the first, but are niore slender; the relation of 

 lengtli between the diflerent joints is almost the same, but the third and fourtli are produced 

 downwards from the apex of the hind margin into a tolerably long process. The claw is very 

 slender, and not curved; the covering of hairs is less rich than in the preceding pair.» 



H. Milne Edwards in 1840 gave the following short description probably taken 

 principally from the drawing of Kroeyek: 



»Antennes inférieures plus longues que les supérieures; leur dernier artide trés-allongé et 

 trés-gréle. Patés de la troisiéme et de la quatriéme paire allongées. Lame terminale de Tabdo- 

 nien triangulaire et pointue au bout. Article basilaire des derniéres fausses patés trés-étroit et 

 allongé.» 



A. Boeck in 1870 instituted the new species Parathemisto ahyssorum with the follow- 

 ing diagnosis, which he repeated in 1872: 



»Carina spinas retroversas non formans. Pedes 3tii et 4ti jDaris articulo 4to subangusto. 

 Pedes 5ti paris articulo 3tio parum modo breviore qvam 4to. ^) 



From his very incomplete description of 1872 I translate what he says about the 

 first and second pairs of perseopoda for a comparison with Kroeyers description: 



»The carpus of the first pair of legs is broad, provided on the hind margin with stout 

 bristles, and is not produced into a heel; the hand (= metacarpus) is about as long as the carpus 



^) This last statement is evidently an error as it is quite contrary to what he hiinself deliiieates on plate 

 ••i. fig. 1 n, and to what 1 have seen iii his own type speciraeu, which lies before me. 



