118 
CLAVELLA SCI A THE RIG A, N. SP., A PARASITIC 
COPEPOD OF GADUS MORRHUA. 
By W. HAROLD LEIGH-SHARPE, B.Sc. (Bond.). 
(With 8 Text-figures.) 
Habitat and Record. 
The animal under consideration belonging to the family Lernaeopodidae was 
taken on a codling (Gadus morrhua), 13 ins. in length, caught at Plymouth 
several years ago, and preserved in formalin since that date. Although about 
twenty-six valid species of Clavella have been either recorded or described in 
detail, the subject of the present paper differs from them all in combining 
several of the more prominent characters of other species, notably the extreme 
length of the backwardly-arched cephalothorax taken together with the 
reduction of the “arms” (second maxillae) and their expansion into a disc so 
that the “bulla” or button appears to be almost directly affixed to the body. 
For this species I accordingly propose the name Clavella sciatherica. 
One female specimen was taken from the first left gill slit, a second from 
the second right gill slit, a third (the longest) from the floor of the pharynx, 
while from the crescentic cushion upon which are borne the vomerine teeth 
two immature females without ovisacs, with two males adhering to each as 
indicated in Fig. 5, were obtained 1 . 
The Females. 
Body. The outline of the animal is best seen from Figs. 1 and 2. The 
length of the specimens differs considerably, but the proportions are constant. 
The dimensions of the medium-sized specimen are: Cephalothorax 5 mm., 
Trunk 2 mm., Ovisacs nearly 4 mm. 
The general colour and appearance is that usually exhibited in this family. 
The trunk is a clear white while the ovisacs are yellow. 
The Cephalothorax is greatly elongated, being more than twice as long as 
the trunk. It is deflected backwards in a characteristically arched manner, 
but not so as to touch the dorsal surface of the trunk. It is unprovided with 
a dorsal carapace and forms a “neck” which is dilated at the base where it 
joins the trunk from which it is distinctly separated. 
1 Since recording the above, Michael G. L. Perkins, who followed my work, has presented me 
with upwards of a dozen specimens of Clavella , all of them of this new species though consider¬ 
ably larger in size, taken from various codling caught at Lowestoft in August 1918. The animals 
were located either on the roof of the buccal cavity, or on the floor of the pharynx, at the bases of 
the gill-arches, never on the gill-filaments. 
