— 151 — 



(3) by directly following the metamorphosis oftheLeptocephali into small 

 eels in the aquarium. They showed at the same time that the metamorphosis here as 

 in the larvae of the conger and other eels was accompanied by a diminution in breadth and 

 length. All these points are determined with great certainty by Grassi and Calandruccio. 

 Since Grassi and Calandruccio's observations, only two Leptocephali have been 

 determined to the species of eel to which they belong, namely, Leptocephahis Grassn 

 Eigenmann and Kennedy, which is referred by its two American authors Eigenmann and 

 Kennedy to the American freshwater QQ\{Ang7n7la chrysypa^). Their figure ofZ. Grassn 

 s shown here in Fig. 3. Further the American Chas. H. Gilbert has demonstrated the 

 metamorphosis of the Leptocephalus of Albula viUpes into its adult form. 



We see from the foregoing that it was the investigation of the developmental history 

 of other species of eels (chiefly the conger) which led to the discovery, that the common 

 eel {Anguilla) also undergoes a metamorphosis and that the larval form is Lepto- 

 cephakis brevirostris. There still remains to describe the discovery of the eggs of 

 eels in the sea as also what is known concerning the occurrence and distribution of the 

 larvae of the common eel. 



2. Distribution and occurence of the larvae of the common eel. After Kaup 

 had described the Leptocephalus brevirostris from the Messina Straits in 1856, it 

 has often been found there 2, and in greatest numbers by Grassi and Calandruccio 

 (1. c. p. 9) , who in March 1 895 found as many as several thousands in one day 

 stranded on the coast in the neighbourhood of Faro. It is due to the peculiar whirl- 

 pools of the Straits that the Leptocephali are brought up to the surface, with the 

 result that, along with other forms both from deep water and from the surface, they 

 can be found there in shallow water and even in the harbour of Messina. How common 

 and well-known the Leptocephali, at least the larger kinds, are at Sicily is shown by 

 the fact, that they are often taken by the fishermen in small nets (for example, during 

 shrimping) and at several places they even receive special names (as at Palermo "lombrici 

 or vermicelli di mare"). At Catania the Leptocephali are called "morenelle" (i. e. small 

 Muraena), which seems to show that the fishermen there have recognised their affinity to 

 the Muraenidae. To return to Leptocephalus brevirostris, Grassi and Calandruccio 

 state that the best way of obtaining specimens is to examine the stomachs of the sunfish 

 {Orthagoriscus mo la), which feeds on them in quantities and which at times at least is 

 very common in the Straits of Messina. In this way Grassi and Calandruccio were 

 able to examine a large number of specimens of the larvae of the eel there and also 

 found them at Catania. 



The Straits of Messina with its powerful whirlpools, which bring up deep-water or 

 even bottom forms and intermingle them with the ordinary inhabitants of the surface, is 



1 Eigenmann and Kennedy (Bull, of the U. S. Fish Commission, vol. XXI for 1901, Washington 1902). 

 Reference will be made later to this paper. 



2 cf. Kauf, On some new genera and species of Fishes collected by Drs. Haeckel and Keferstein at 

 Messina (Annals and Mag. Nat. History, 3 ser., vol. VI, London, i860), where pag. 272 the author describes a 

 specimen from Messina which "exhibits all the characters of that figured by me, except that it has a rather 

 more pointed head and a somewhat longer tail". The length of the body was 48 mm., the length of the tail 

 21 mm. Strömman also (I. c. p. 11) mention? a specimen taken on March 14th, 1891 in Messina harbour by Dr. 

 BovALLlUS. Its total length was 51 mm., the tail 14 mm. and greatest height of body 10 mm. 



