COTTUS HECILOPU8. 



55 



both fins the rays are undivided. The head is relatively small, but is contained 

 four times in the entire length. The least height of the tail is one-fourteenth 

 of the length. The snout is more pointed, the eyes are separated from each 

 other by their own diameter, and are the same distance from the snout. They 

 are rather smaller than in the other variety. 



The villiform teeth in both jaws are longer and thinner than in Coitus, 

 gobio. The skin nowhere shows pores or traces of rough, bony depressions. 

 There are usually one or two fewer rays in the anal fin. 

 The males have a thicker head and broader mouth than the 

 females. Their bi-lobed milt is not covered with a dark peri- 

 toneum such as wraps round the simple heart-shaped ovary 

 of the female. The largest examples are three inches long, 

 but frequently the fish does not exceed half this length. 

 Its distribution is more southern than that of the other varieties, being known 

 from the Lake Garda, from Xegar in Dalmatia, and from Servia. 



Fig. 23. HEAD 



OF COTTUS FER- 

 RUOIN'EUS, SEEX 

 FROM THE 



i'KOXT. 



Cottus poecilopus (HECKEL). 



1 D. 89, 2 D. 1618, P. 14, V. 1/4, A. 1314, C. 13. 

 This species (Fig. 24) closely resembles the preceding, so that it is chiefly 

 necessary to indicate such differences as distinguish it. The eyes approximate 



Fig. 24. COTTUS PO3CILOPUS (HECKEL). 



more closely together, being separated by less than their own diameter. 

 The hatchet-shaped free opercular spine, which curves forward, is beneath the 

 thick skin. The ventral fins are somewhat longer ; they commence just under 

 the pectoral fins, and reach back to the vent. The pectoral fins are some- 

 what shorter, and reach as far back as the beginning of the second dorsal. 



