CALIGUS MINIMUS. 47 



1901. Caligus minimus A. Scott. (107) vol. xv, p. 349, pi. i, figs. 1-8. 



1905. Caligus minimus T. Scott. (110) p. 109. 



1906. Caligus minimus Norman & T. Scott. (88) p. 205. 

 1906. Caligus minimus A. Brian. (21) p. 36. 



Female. — Carapace siiborbicular and scarcely equal 

 to half the entire length ; frontal plates and lunulas 

 large. Eves conspicuous. Free thoracic segment 

 narrow. Grenital segment rather less than a third of 

 the total length, and equal in width to about two- 

 thirds that of the carapace ; the postero-lateral angles 

 somewhat produced into narrow rounded lobes. Abdo- 

 men uniarticulate and narrow, becoming slightly 

 expanded anteriorly, equal in length to about two- 

 thirds that of the genital segment. Caudal rami 

 about half as long as the abdomen. 



Antennules short ; end joint tolerably elongated and 

 narrow. Sternal fork small, the stem moderately 

 long with short and somewhat divergent branches. 

 Fourth pair of thoracic legs tolerably elongated, basal- 

 joint stout, ramus two-jointed, joints subequal, the 

 first with a small spine on the outer distal angle, the 

 second furnished with one moderately long and two 

 short apical spines as shown in the figure (PI. XXV, 

 fig. 15). The fifth pair consisting each of a minute 

 setiferous plate near the postero-lateral corners of the 

 genital segment. 



Male. — The male is larger than the female, and 

 differs from it chiefly in the form of the genital 

 segment; this segment is not much wider than either 

 the free thoracic segment or the abdomen. The 

 appendages are somewhat similar to those of the 

 female, except that the second maxillipeds are con- 

 siderably expanded distally, and are each armed with 

 a strong claw, so that they form powerful grasping 

 organs. The branches of the sternal fork in the male 

 are scarcely if at all divergent. 



Total length of the female about 5 mm., and of the 

 male about 7 mm. 



Habitat. — Parasitic on the bass, Labrax lupus. 

 Usually found inside the gill-covers, or in the mouth of 



