64 The Irish Naiuralist. [March, 



The dorsal filament springs from an elevation, and the axis 

 of the smooth basal region appears to be cartilaginous. 

 There are nine pigmented processes, but the first three are 

 small. The last (most distal) has the proximal three-fourths 

 thicker and deepl}^ coloured with pigment, the distal region 

 being pale and flattened, with the terminal edge bevelled from 

 above downward. They thus agreed with Dr. Emery's figure 

 10, tav. ii., from the larval form of Fierasfer acus, though 

 possibly F. dentatus may show a similar condition. 



No example of Fierasfer acus appears to have been procured 

 in Britain, but one or two specimens of F. de7itatus have 

 been got on the west coast of Ireland, and Mr. T. Edwards, 

 of Banff, found several young forms, in March, about 5 or 6 

 inches in length near the shore on sandy ground. The Moray 

 Frith is rich in holothurians, and in other respects it is a 

 suitable habitat, for in this area southern forms occur which 

 are elsewhere absent on the eastern shores. Mr. Boulenger 

 had kindly examined two of these in the British Museum. 

 The largest is 79 mm. long. A low conical tubercle exists in 

 front of the dorsal fin, but apparently no distinct spine. The 

 anterior canine-like teeth are very prominent. The tail ends 

 in a hair-like process. Only a few spots of pigment occur on the 

 head in the preparations. The absence of teeth in the Valentia 

 specimen would indicate that it belongs to a different species 

 from those in the British Museum, and therefore probably to 

 Fierasfer acus, a form hitherto absent from Britain. The 

 early appearance of such prominent teeth in the post-larval 

 Teleosteans would lead us at least to expect a trace of their 

 presence at 76 mm., especially since they are so characteristic 

 at 79 mm. In any case the occurrence of this stage in the 

 development of Fierasfer at Valentia is most interesting, and 

 it is to be hoped that the eggs may yet be obtained in that 

 region. 



University of St. Andrews, Scotland. 



