LEPEOPHTHEIEUS STURIONES. 75 



terminal claws, which have their ends bent at nearly 

 a right angle to the basal part. Mandibles small, 

 and resembling those of Lepeophtheiru* pectorali*. 

 Second maxillse stout, and dividing at the apex into 

 two slightly bent teeth. Second maxillipeds mode- 

 rately stout and elongated, and armed with short but 

 strong terminal claws. Sternal fork very stout, with 

 short rami which are stout at the base and taper to a 

 tolerably sharp point, the rami distinctly divergent. 

 Fourth pair of thoracic legs robust, ramus moderately 

 elongated and composed of three joints, the middle 

 joint being rather longer than the first or third ; the 

 outer distal angle of the first joint terminating in a 

 minute tooth, a tolerably stout spine springing from 

 the outer distal angle of the second joint, the end joint 

 armed with apical spiniform setae of unequal length, the 

 innermost being considerably longer than the other two, 

 and the outermost the shortest. Length about 14 mm. 



We have not seen the male of this species. 



Habitat. Found as a parasite on the sturgeon, 

 Acipenser sturio Linn. Obtained on a sturgeon 

 captured about sixteen miles south-east of Aberdeen 

 and landed at the Fish-Market there, 29th December 

 1904. We are indebted to Dr. Alexander Bowman 

 for this specimen. 



This species does not appear to be a very common one. 



Genus 8. LUTKENIA Glaus, 1861. 



Syn. Cecropsina Heller, 1865. 



Carapace obcordate, or nearly round, without frontal 

 plates. Antennules two-jointed. Fourth ring of the 

 thorax covered by small dorsal plates. Grenital seg- 

 ment prolonged backwards in the form of lobes. 

 Abdomen short, not jointed, and terminating in two 

 small caudal plates. 



The first pair of thoracic legs consisting of one or 

 two branches, but the inner branch, when present, very 

 small. The next three pairs two-branched. Both 



