42 NOTICES OF SERIALS. 



Insinuated below, and the seventh, which is rounded there, scarcely more than 

 a third of the depth of their respective segments. Upper pair of Antenna long 

 enough to reach to the hind margin of the fifth segment. Scape shorter by a 

 fifth than the flagellum; composed of obconical joints, the first as long as the 

 head; the second shorter and thinner than the first by about a fourth ; third 

 half the size of the second. Flagellum setaceous, composed of 16 to 25 joints, 

 which become gradually longer towards the middle of the flagellum. Accessory 

 flagellum a little longer than the first joint of the primary one ; the first joint of 

 it subcylindric ; the second conical, about a third the length of the first. Lower 

 pair of Antennae about a third part shorter than the upper. Scmpe nearly twice 

 the length of flagellum ; the first two joints the shortest, and nearly equal to one 

 another ; the third and fourth nearly equal, each about three times the length of 

 the second ; the third subclavate ; the fourth subcylindric, and rather more slen- 

 der. Flagellum setaceous, of 7 to 9 joints, the length of which is variable, but 

 usually not very unequal. Mandibular not longer than they are broad at the 

 base, five-toothed ; the apical tooth and the hind one elongated, the molar small 

 and oval. Palpi two and-a-half times the length of the mandibulse ; the second 

 joint clavate ; the third elongate oval ; the two of equal length, and nearly thrice 

 as long as the first. First pair of Maxilla with the exterior mala armed with seven 

 spines, each of which has a single tooth inside behind the middle. Maxillary 

 feet with their exterior mala armed with a row of small blunt spines along the 

 inner edge, and some longer sharp ones at the apical angle. Palpi one-half 

 longer than the mala, the ratio of the joints : : 2 : 1 : 2£ : 3£ : 3. First and second 

 pair of feet with the hand ovate, compressed, longer by a third than brdad, and 

 furnished with a compressed obtuse spine at the middle of the hind margin ; 

 second pair a fourth longer than the first; theratio of the joints ::6: l£: 1J: 3:6: 5^. 

 Third and fourth pairs equal, slender, a fourth longer than the second pair ; the 

 ratio of the joints : : 6 : 1 : 4 : 3 : 3§ : 1^. Fifth, sixth, and seventh pairs alike in 

 form, but increasing in size successively ; the fifth nearly a fourth part longer than 

 the fourth, and the seventh nearly twice as long as this ; ratio of the joints : : 4 : 

 1:3^: ;^§ : 4: f. Eighth, ninth, and tenth pairs resembling each other; 

 the paddles flagelliform, many -jointed, their natatory bristles longer, ciliated 

 in a single row, obsoletely jointed behind the middle. Last three pairs of 

 feet formed for springing ; eleventh nearly twice as long as the segment that 

 bears it ; the styles equal, about a fourth part shorter than the basal plate ; twelfth 

 pair half the size of the eleventh, but like it in the form and proportion 

 of the joints. Basal plate of the last pair of feet twice as long as the last 

 segment ; the interior style as long as a sixteenth part of the exterior style in 

 the male, — as a seventh part of it in the female, furnished at the tip with two small 

 spines, and a feathered bristle. Exterior style cylindrical ; the first joint in 

 the male thrice, — in the female twice as long as the basal plate, bedecked with 

 tufts of short spines at each side, which are less conspicuous in the male, the 

 outside tufts composed of two spines and a feathered bristle; second joint, in the 

 male, about as long as the first, glabrous, perfectly smooth, with the tip alone 

 tufted, — in the female, about half as long as the first joint, with tufts of minute 

 bristles on the sides and at the tip. Claws of all the feet imperfectly jointed 

 befor© the tip, and armed with a minute spine, inside, near the spurious joint. 

 Caudal appendage as long as the last segment, deeply incised, bilobed ; the lobes 

 subovate ; the tip truncated, three-spined ; the outer edge with two incisions, the 

 inner with one, each of which is armed with a single spine. 



[Extracted from the Danish Royal Society's Transactions for 1851, and Pro- 

 ceedings for 1855.] 



