318 Dr. J. U. Tosh on the 



Of a total of 892 fislies examined 236, ov 26*4 per cent., 

 were infected with tapeworm. Tt would be interesting to 

 know if the falling off about October were at all constant, 

 and, if so, wliether the rise in November was connected with 

 a final feast before the dash for the river. 



Tetrarhynchus grossus, Eud. Synops. pp. 129 & 448, pi. ii. 

 figs. 9 & iO. (PI. V.) 



This form, known to the salmon-fishermen of Ber\vick-on- 

 Tweed as a " flatty/' occurs in the abdominal cavity of bith 

 salmon and sea-trout, and is more often dead than alive. 

 The live form is found almost invariably attached by its 

 proboscides to the outside of the lower intestine near the 

 vent. It is cream-coloured and soft, with parallel strife on 

 the flattened body behind the head. If touched or detached 

 it contracts actively. When preserved the striated part 

 becomes rugose and sometimes almost tuberculated. A 

 preserved specimen sent by the late Dr. Johnston from 

 Berwick-on-Tweed was described and figured by Dr. Baird 

 as T. rugosus *. 



If unable to pass to the intestine of another host, e. g. 

 shark, where it would most likely become sexual, the worm 

 after some time seems to die, loosens its hold, drifts forward 

 in the body-cavity, and usually becomes embedded in a soft 

 organ, such as the liver. There it is pressed out of shape, 

 becoming often triangular in section or bent on itself. The 

 head retains most of its former bulk, but the body becomes 

 stiff and attenuates. Sometimes specimens are found with 

 the flesh coming away in irregular layers from the body. 

 The surrounding tissue is often affected by this process of 

 degeneration. Specimens in this stage were described and 

 figured by Drummond as T. solidus f. 



In the accompanying Plate the process of degeneration is 

 illustrated. Fig. 1 is T. grossus from a preserved specimen ; 

 fig. 2 has a head and body of T. solidus and a tail of 

 T. grossus, and shows the papilla where the strobila would 

 have budded. 



Von Siebold considers his T. claviger\ to be identical with 

 T. grossus, and most likely all the species listed by him on 

 p. 235 {loc. cit.) are synonyms ; but he places the T. solidus 



* Catal. Entoz. Brit. Mas. p. 69, tab. ii. fig. 3. 

 t Charlesworth's Mag. Nat. Hist. vol. ii. (1838). 

 X Zeitschr. wis.?. Zm\. Bd. ii. 



