Gobioidei, Discocephali, and Taeniosomi 469 



20 to 22 plates in its disk, and the sides are marked by a dusky 

 lateral band. 



Almost equally widely distributed is the smaller remora, 

 or shark-sucker (Echeneis remora}, with a stouter body and 

 about 1 8 plates in the cephalic disk. This species is found 

 in Europe, on the coast of New York, in the West Indies, 

 in California, and in Japan, but is nowhere abundant. Another 

 widely distributed species is Remorina albescens with 13 plates 

 in its disk. Remoropsis brachyptera, with 15 plates and a long 

 soft dorsal, is also occasionally taken. Rhombochirus osteochir 

 is a rare species of the Atlantic with 18 plates, having the pec- 



FIG. 424. Rhombochirus osteochir (Guv. & Vol.). Wood's Hole, Mass. 



toral rays all enlarged and stiff. The louse-fish (Phtheirichthys 

 lineatus) is a small and slender remora having but 10 plates 

 in its disk. It is found attached, not to sharks, but to barra- 

 cudas and spearfishes. 



A fossil remora is described from the Oligocene shales in 

 Glarus, Switzerland, under the name of Opisthomyzon glaronen- 

 sis. It is characterized by the small disk posteriorly inserted. 

 Its vertebrae are 10+13 = 24 only. Dr. Storms gives the follow- 

 ing account of this species: 



"A careful comparison of the proportion of all the parts 

 of the skeleton of the fossil Echeneis with those of the living 

 forms, such as Echeneis naucrates or Echeneis remora, shows 

 that the fossil differs nearly equally from both, and that it was 

 a more normally shaped fish than either of these forms. The 

 head was narrower and less flattened, the preoperculum wider, 

 but its two jaws had nearly the same length. The ribs, as 

 also the neural and haemal spines, were longer, the tail more 

 forked, and the soft dorsal fin much longer. In fact it was 

 a more compressed type, probably a far better swimmer than 



