Reviews — M. Lohest — Devonian Fishes of Belgium. 41 



but their determination is interesting on account of their intimate 

 association with truly marine fossils. Until the appearance of the 

 present work only four specimens had been critically examined and 

 described (Holopty chins Omaliusi, Pahedaphus insignis, JPaladaphua 

 devoniensis and Byssucanthus Gosseleti) ; and palasiohthyologists are 

 indebted to M. Lohest for the care and perseverance with which 

 he has collected, examined, compared, and described all available 

 material. 



A brief introduction summarizing the present state of knowledge 

 of the Belgian Devonian fish-fauna is followed by the systematic 

 and descriptive part, which occupies fifty pages, and is illustrated by 

 eleven plates. Eight genera and fourteen species are determined, 

 and most of the descriptions are accompanied with good figures 

 drawn by the author. Two forms of teeth from Strud are assigned 

 to Dendrodus, the one believed to be identical with certain gently 

 curved teeth commonly associated with D. sigmoides and now named 

 D. Traquairi, the other regarded as hitherto unknown and named 

 D. Briarti. Lamnodus is accepted as a sub-genus of Dendrodus, and 

 an imperfect tooth from the Upper Famennian of Liege is described 

 as L. minor, sp. nov. ; the genus Cricodus receives a doubtful portion 

 of dentary, named Cricodus'? Agassizi, sp. nov.; and then follows 

 a long section upon Holoptychius and its Belgian representatives. 

 M. Lohest has studied the fine specimens in the British Museum, 

 besides others at Edinburgh, and treats of the squamation, especially, 

 in considerable detail. As the result of his researches, he recognizes 

 great variation in the scales of different parts of the body, but 

 considei's that detached examples are usually specifically determin- 

 able when their outline is distinct ; for the scales of corresponding 

 parts in the various species are almost identical in shape and pro- 

 portions, only differing in thickness and the arrangement of the 

 external ornamentation. Some isolated bones of the genus are 

 first noticed, and then follows a section upon the supposed teeth of 

 Holoptychius, which appear to be identical with so-called Lamnodus 

 previously described. The typical II. nobilissimus is regarded as 

 not certainly met with in Belgium, and the author considers that 

 both Agassiz and the British Museum include under this species 

 some scales of forms that are truly distinct. To us, however, it 

 appears that the scales now named H. Dewalqnei can be so closely 

 paralleled by examples found in close association with the true 

 H. nobilissimus of Clashbennie that there is no justification for 

 their specific separation. Several fine specimens of these scales are 

 figured ; and an equally good series of very thin scales, exhibiting 

 a nearly similar ornament, is described and figured as H. inflexus, 

 sp. nov. Other scales are identified with the well-known Scottish 

 species, H. giganteus and H. Flemingi. A brief discussion of 

 Glyptolepis results in the conclusion that its scales only differ from 

 those of Holoptychius in their comparative tenuity ; and some small 

 specimens from Strud ax - e assigned to G. Benedeni, sp. nov., and 

 G. radians, sp. nov. 



After the description of the " Cyclodipterines," the arrangement 



