NO. 14 MILLIPEDS OF WEST INDIES AND GUIANA — LOOMIS 35 



Family PLATYRHACHIDAE 



NANORRHACUS LUCIAE (Pocock) 



Plate I, fig. 7 



Platyrhachus luciae Pocock, Journ. Linn. Soc. London, vol. 24, pp. 51 1-5 12, 

 1894. 



Numbers of specimens were found in the forest on the Bar de 

 risle above Castries, St. Lucia, February 2, 1932. 



Family POLYDESMIDAE 

 AETHEANDRA, n. gen. 



Type. — Aetheandra multiplex, n. sp. 



Diagnosis. — The relationship of this genus may be close to Poly- 

 desmiis — at least the females suggest this possibility — but the males 

 exhibit more diverse secondary sexual characters than previously 

 associated with this family, such as the greatly broadened labrum, 

 the posterior productions of segments 2 and 3, and the expanded 

 joints of legs 2 and 3. In remarkable contrast to the diversity of 

 the secondary characters, the gonopods show a degree of simplicity 

 probably not equaled by any other member of the order. 



Description. — Small, very agile millipeds with the body of the pro- 

 portions of a small Polydesnms. Number of segments 20. Lateral 

 carinae horizontal, marked off from the body proper by a broad longi- 

 tudinal depression ; a more definite, transverse depression across the 

 dorsum. Dorsum and lateral margins of the keels with a few thick- 

 ened setae, but lacking any polygonal areas or tubercles, the surface 

 finely granular. Pores in the usual sequence, opening on the dorsal 

 surface from the base of the produced posterior angles. Males ex- 

 hibiting unusual secondary sex characters in various parts of the body. 



Head with the antennae long and slender; joints 2 to 6 subequal in 

 length but joint 6 suddenly widened on the outer side beyond the small 

 base. Vertex medianly impressed, glabrous behind, but in front to 

 the upper limits of the antennal sockets it is finely pubescent. Males 

 with a prominent transverse tubercle on the front just below the an- 

 tennae ; also with a continuous ridge connecting the lateral angles of 

 the head ; on each side the ridge begins at the angle and passes in front 

 of the antenna and curves up between it and the frontal tubercle, 

 joining the ridge from the other side high on the vertex where it is 

 less prominent ; labrum broadened, the front margin nearly straight 



