CLAVELLA SCOMBRI. 219 



1901. Aachorella scombri T. Scott. (113) p. 135, pi. viii, fig. 3. 

 1906. Anchorella scomberi A. Scott. (110) p. 53, pi. vii. 

 1906. Clavella scombri Brian. (21) p. 116, pi. x, fig. 6. 



Female. — Ceplialo thorax extremely elongated, flex- 

 nose, vermiform, and nearly three times as long as 

 the genital segment, the proximal half moderately 

 stout, the distal portion rather more slender. More- 

 over, the proximal portion of the cephalothorax bends 

 gently downwards, but near the middle there is a 

 somewhat abrupt change of curvature in the opposite 

 direction, which causes the cephalothorax to assume 

 a geniculated or sigmoid appearance. Genital seg- 

 ment of a subglobular form, rather longer than broad, 

 and small in comparison with the cephalothorax, also 

 appearing to be unprovided with distal appendages 

 of any kind. Abdomen rudimentary or obsolete. 

 Egg-strings small and saccate. 



Antennules small, two-jointed, and furnished with a 

 few small apical setas. Antennas short, stout, and 

 somewhat rudimentary ; outer ramus very small. 

 Mandibles and other mouth-organs similar to those of 

 Clavella emarginata. Second maxillipecls entirely 

 coalescent, extremely short, and united at the apex 

 to a small horn-coloured chitinous plug. Length, ex- 

 clusive of the cephalothorax, about 2'5 mm. Length 

 of cephalothorax fully 6 mm. 



Male. — Extremely small, and its form that which 

 appears to be characteristic of the males of this genus, 

 being very short and with the dorsum elevated so that 

 the height is distinctly greater than the length. Both 

 pairs of maxillipecls short, stout, and strongly uncinate. 



Habitat. — Parasitic on the gill-arches of mackerel 

 {Scomber s'combrus). Found on mackerel captured 

 in the neighbourhood of Aberdeen in August, 1900 

 (T. Scott). On mackerel captured in the Irish Sea 

 off Walney Island, and in Carnarvon Bay in 1905 

 (A. Scott). Recorded by Dr. Ed. Graeffe as parasitic 

 on mackerel captured in the Gulf of Trieste.* 



* 'Arbeiten dcr zoolog. Tnstitut zu Wien/ T. xiii, Heft 1, p. 17 (1900). 



