63 
1921-22.] Myriapods from Mesopotamia and N.W. Persia. 
tracheal stalk has been overestimated, and that one or other of the two 
structures (stalk fused or free) has to be looked upon as a peculiar case, 
evidently connected with local environmental conditions. It is conse- 
quently proposed to give these structures a secondary rank amongst the 
family characters, which ought to stand as follows : — 
Gonapods deeply split, the mesomerite being by far the larger of 
the two parts, the solenomerite being provided with a more or less 
developed coxal base and an apical slender process, and being often 
“ trimmed ” with hyaline lamellae. In four cases out of five the meso- 
merite articulates freely with its tracheal stalk, while in the remaining 
case these organs are fused. 
Peltogonapods more or less developed, with or without a flagellum ; 
when present, the latter is often short. 
The family remains divided into two sub-families, according to the 
existence {Pcectophyllince) or the absence {Gatamicrophyllinw) of a pelto- 
gonopodial flagellum, Calyptophyllum taking its place in the former. 
In the Pmctophyllince two genera are already inscribed, i.e. Poicto- 
phyllnm and Macheiroiulus ; both may be known by the peculiar size and 
shape of the mesomerite and 637 the absence of the lamellar expansions 
of the solenomerite. 
Calyptophyllum ohvolvatimn, n. sp. 
; Length about 42 mm.; diameter, 1*95 mm.; 70 segments; 127 pairs 
of legs ; 3 segments apodous. Adult. 
Colour uncertain, the only specimen being dry, in which state it is 
black, with pale brownish limbs. 
Head short and broad, smooth, with occipital and transverse sulci 
particularly thin, though corresponding to well-defined internal apodemas, 
The transverse sulcus is accompanied by only one (right) dimple, the seta 
of which is rubbed off; it is not possible to decide whether the animal 
possesses occipital setae or not. Four labial setae. Labial excision 
extremely shallow. Ocelli distinct, some 52 in number (9, 10, 9, 8 , 7, 5, 4), 
gathered on a large, rounded, dark patch. Antennae of moderate length, 
reaching the posterior margin of the third segment. No apical sensory 
cones (broken ofl* by accident ?). 
Mandibular stipe provided with a rounded, projecting callus. Four 
pectinate lamellae. Gnathochilarium (fig. 6 ) with a very small promentum, 
not exceeding one-third of the length of the lingual lamellae. Two short 
setae on each side behind the middle. None of the palpi show sensorial 
