REPORT ON THE ISOPODA. 3 



p. 53, pis. i. and ii., another species of Serolis under the name of Brongniartia triJo- 

 hitoides, which name was subsec[iiently altered by Audouin and Milne-Edwards into 

 Serolis trilohltoides, since there was evidently no generic difference from Serolis para- 

 doxa ; this paper contains merely a description of the new form, accompanied by figures 

 ill which the whole animal as well as the mouth appendages and the two first abdominal 

 limbs are displayed ; a figure of a Trilobite, Paradoxus boltoni, is given for the purpose of 

 comparison, but there is no account in the text of any supposed resemblances between 

 the two forms, except the similarity of the eyes. It seems not unlikely that this species 

 is identical with Studer's Serolis cornvta, or at most a local variety. This species was . 

 obtained on the coast of Patagonia from the stomach of a fish belonging to the genus 

 Phycis, and also from the South Shetlands. 



The next contribution is a paper by Audouin and Milne-Edwards, which was pub- 

 lished in the Archives du Museum for 1S41. This important memoir on the genus 

 Serolis contains, after an historical introduction in which all the previous notices regard- 

 ing the genus are reviewed, a general account of its external characters, and a description 

 of four species — Serolis paradoxa, Serolis trilobitoides, Serolis orhignyi, and Serolis 

 gaudicJiaudii, the two last being here described for the first time ; the memoir is illus- 

 trated by figures of these species and of all the essential parts in their anatomy ; with 

 regard to the afiinities of the genus, it is considered as intermediate between the other 

 Isopoda and the Trilobites. Several of these figures are repeated in the magnificent 

 illustrated edition of Cuvier's Eegne Animale, edited by his disciples Audouin, Milne- 

 Edwards, Latreille, &c., though the text of this work appears only to contain a descrip- 

 tion of Serolis paradoxa. 



The Histoire Naturelle des Crustaces of Milne-Edwards, published in 1840, contains 

 a description of the genus Serolis and of the four species Serolis fahrieii { = Serolis jxira- 

 doxa), Serolis bronr/uiartiana { = Scrolls trilobitoides), Serolis orhigniana, and Serolis 

 gaudichaudii ; in this work Serolis is included in the family Cymothoadaj, which is 

 divided into three tribes — (l) Cymothoadiens ravisseurs, Serolis; (2) Cymothoadiens 

 errans, ^ga, Conilera, &c. ; (3) Cymothoadiens parasites, Cymothoa, Nerocila, &c. 



In 1852 Dana described a new species of Serolis {Serolis -plftnits) in the Crustacea of 

 the United States Exploring Expedition. 



Six years later (1858) another species was described by Liitken, to which he gave the 

 name of Serolis sehythei. 



The next and a most important contribution to our knowledge of Serolis is Grube's 

 Monograph of the genus, published in 1875. Besides the description of a new species 

 [Serolis tubercidata), a general resume of the extei'nal characters of the genus, and some 

 notes on certain species {Serolis paradoxa and Serolis sehythei) that had been previously 

 described, are to be found in this paper, together with a complete list of the then known 

 species, eight in uumljcr. Grube regards Serolis as being most nearly allied to SphcBroma. 



