182 Prof. M'Intosli's Notes from the 



is interesting to note how persistently the larval and post- 

 larval forms of some species occur for months. Any danger 

 wliich a limited spawning-period might engender is thus 

 obviated. As soon as the later stages are reached, with the 

 exception of Tomopterisj they cease to be pelagic, and have 

 to be souglit at the bottom or between tide-marks. 



2. On the British Species of Spinther. 



In his recent elaborate account of the genus Spinther * 

 Prof. L. von Graff has placed the form I had mentioned as 

 Spintlier oniscoides, Johnst., under Spinther arcticus, Wiren. 

 The British form referred to was procured in the beginning 

 of August 1865 from the long lines of the fishermen in the 

 Minch. It was small, dead or nearly so, and rapidly decom- 

 posing, so that the dorsal lamella and other parts were 

 injured. The original specimen of *S'. oniscoides is not in the 

 British Museum, and is thought by Prof. Jeffrey Bell to have 

 been lost, and some doubt then existed as to the minute 

 characters. It differs from the other species which have been 

 subsequently discovered, especially in regard to the cirrus on 

 the parapodia and the presence of bristles with simple tips in 

 the dorsal lamella?. 



A minute examination of the Hebridean specimen, however, 

 shows that while the species is not Spinther oniscoides, 

 Johnston, it is certainly not S. arcticus, Wiren- The contour 

 and general structure approaches that of S. miniaceus, Grube, 

 and in this Prof, von Graff now agrees with me. No cirrus 

 is present, and the free lateral (circumferential) lamella diverge 

 from the condition in tlie other two forms mentioned. The 

 bristles of the dorsal lamelk\3 are bifid, any simple tips seen 

 in the preparations being due to position (on edge). The 

 ventral surface is marked by rows of minute warts, while the 

 pharyngeal region in protrusion forms a smooth trumpet-like 

 expansion, and thus differs from the organ in S. arcticus. 



Spinther is one of the rarest British Annelids, and seems 

 to be confined to the western shores. The Irish coast should 

 be specially searched, as it is very desirable to have an 

 example of the original species described by Dr. Johnston, 

 which was sent to him from Belfast Bay (6-10 fathoms). 



3. On the Young Stages of the Gunnel (Centronotus 

 gunncllus). 



In the paper on the " Development and Life-histories of 

 Teleostean Pishes " an account is given of the gunnel from 

 * Arbeilou aiu> d. Zoolog. Institut zu Graz, ii, Bd. No. 3 (1887). 



