220 DE. W. T. CALMAN ON APHAREOCARIS, 



latter placed at about one-fourth oE the length of the carapace from the front 

 margin ; the antero-lateral margin sloping backwards from the base of the 

 antennules to a very minute pterygostomial tooth ; inter-regional grooves on 

 surface of carapace very indistinct. 



Anterior abdominal somites rounded dorsally, fifth and sixth obscurely 

 ■carinate ; pleural plates of first somite biiobed ; sixth somite twice as long as 

 fifth, measured along dorsal edge. Telson (PL 16. fig. 3) four-fifths of length 

 of sixth somite, acutely pointed, with a longitudinal median dorsal groove, 

 and with five pairs of small marginal spinules. 



Ocular peduncle (fig. 2) about one-third of length of carapace, not reaching 

 end of first segment of antennular peduncle, widening distally ; corneal area 

 occupying less than one-fourth of length of second segment, little wider than 

 adjacent part of peduncle, dark brown with lighter periphery. 



Antenmdar 'peduncle (fig. 2) about four-fifths of length of carapace, the first 

 segment, measured along outer edge, about three times as long as second 

 and four times as long as third ; tooth of outer margin (stylocerite) rather 

 behind the middle of its length, and a second tooth, or vertically compressed 

 lobe, rising from the upper surface just in front of the statocyst and behind 

 the stylocerite ; second and third segments successively narrower. Inner 

 flagellum shorter than peduncle ; outer flagellum about 3^ times as long as 

 peduncle, thickened at base, where it carries a brush of sensory filaments ; 

 no trace of clasping organ. 



Flagellum of antenna (fig. 1) more than twice as long as the body, with an 

 abrupt double bend at about three-sevenths of its length from the base ; 

 marginal setae longer and more conspicuous distal to this bend. Antennal 

 scale about two-thirds as long as carapace and three times as long as wide ; 

 outer margin nearly straight, its terminal tooth considerably surpassed by 

 the rounded distal maroin. 



Mandibular palp (fig. 4) composed of three segments ^, the first very small, 

 the second large and flattened, trapezoidal in outline, about three times as 

 long, and, at its greatest width, three times as broad as the third segment. 



Maxillula (fig. 5) resembling that of Sergestes. 



Maxilla (fig. 6) i-emarkable for the reduction of the endites ; only two are 

 present and these are very small, with one or two minute apical seta3 on each. 



* It is sometimes given as a general character of the tribe Pena3iclea that the mandibular 

 palp is composed of only two segments (Spence Bate, Eep. ' Challenger ' Maci-ura, pp. xxxiv 

 & 226, 1888 ; Bonvier, Res. Camp. Sci. Monaco, xxxiii. Crust. Decap. (Peneides) p. 9, 

 1908). Kr^yer, however, attributes three segments to the palp of Sergestes (Kgl. Danske 

 Vid. Selsk. Skr. (5) iv. p. 225, 1856), while Boas describes it as three-segmented in Sicyonia 

 and Sergestes, and as having the first segment obscurely or not at all defined from the second 

 in Penceus (Kgl. Danske Vid. Selsk. Skr. (6) i. pp. 31, 34, 36, ]880). I find the small 

 proximal segment quite distinct in Sergestes rohustus, Acetes indicus, Benthesicij7niis in- 

 vestigatoris, and Sicyonia carinata, as in the species here described ; on the other hand, only 

 two segments can be detected in the palp of several large species of Penceus. 



