The Genus Pachyrhamma (Rhaphidophorinae: Orthoptera).
A New Species from New Zealand.
[Read before the Nelson Institute, 1st October, 1924; received by Editor, 5th November, 1924, issued separately, 10th April, 1926.]
Pachyrhamma acanthocera n. sp.
♂. General build and colouring as in P. fascifer Walk., but much larger, and having the colour-pattern much less strongly marked both on body and legs. The peculiarity which distinguishes this species from all the others so far known is that several of the antennal segments carry distinct spines. This peculiarity is emphasized by the specific name, suggested by Dr. R. J. Tillyard. The antennal segments number about 550, the basal one being stout, 3 mm. long, the second short and much narrower but noticeably broader than the rest, which form a long, slender, flexible flagellum; the segments following the second are irregular in length, often only partially divided into two, but, on the whole, steadily decreasing in individual length from the basal ones outwards. Segments 36 and 48 of right antenna, and segments 39 and 48 of left, have a sharp dorsal spine; segments 68, 70, 72 of right antenna, and 67, 69, 71, 73 of left, are distinctly knobbed distally on the outer side; segments 74 and 77 of right antenna, and segments 75 and 77 of left, carry sharp spines placed latero-ventrally on the outer distal margin. Total length of antenna, 183 mm.
Length of body, excluding antennae and cerci, 23 mm.
Breadth of head, 5.5 mm.; length of maxillary palpi, 20 mm.
Thorax: Pronotum 8 mm. long, 7 mm. wide; mesonotum 4 mm. long, 7.5 mm. wide; metanotum 4 mm. long, 7 mm. wide.
Legs: Fore legs—femur 25 mm., tibia 26 mm., tarsus 17 mm.; middle leg—femur 23 mm., tibia 26 mm., tarsus 16 mm.; hind leg—femur 51 mm., tibia 62 mm., tarsus 24 mm.
Abdomen, 9 mm. long; cerci, 9.5 mm.
Total length of specimen from tip of antenna to end of hind leg when placed in natural position, about 305 mm., or, roughly, just over 12 in.
Locality.—Waitakere Ranges, north of Auckland; February, 1923.
Types.—Holotype and paratype males in Cawthron Institute collection. The measurements given are those of the holotype male; the paratype is about the same size, but has the knee-joints of the middle and hind left legs deformed.