The first three males and one additional egg-bearing female have been taken in 80–300 fathoms since 1951. A list of the 19 species of Nephrops known up to 1951 is given and N. challengeri is compared to both N. thomsoni and N. sibogae, both close Indpacific forms A prominent colour pattern of bright red. brown and pink on white with blue eggs is described.

Spence Bate (1888) dealing with the macrura collected by H.M.S. Challenger during the years 1873–76, described a new species, Nephrops thomsoni, based on a male collected from 100 fathoms between Samboangan and Manila, Philippine Islands, and on two females from 275 fathoms in the Tasman Sea, off Cook Strait. New Zealand. Bate describes only the male in detail, listing the main differences between it and the females, as he considered these differences to be only sexual. He illustrates both sexes in dorsolateral view on Pl. XXV, Figs. 1 and 2 in his report He figures some appendages and gills from the male on his Pl XXVI, but no further data for the female.

Balss (1914) having examined females of N. thomsoni from Formosa, recognised that two species were involved. The Philippine male being the type of Nephrops thomsoni, he proposed the new name N. challengeri for the females from the Tasman Sea. The type of N. challengeri is therefor the female illustrated on Bate's (1888) Pl. XXV, Fig. 2, with its description as given there consisting only of the list of differences on page 191 of the latter's report and to date no full account of the female nor any account of the male of N. challengeri has been published.

De Man (1916) described a closely allied species of Nephrops, N. sibogae, from 170 fathoms off the Kei Islands, in the Arafura Sea, between Dutch New Guinea and Timor, collected by the Siboga Expedition during 1899–1900. He compared his species with both N. thomsoni and N. challengeri, finding it intermediate, but was handicapped in his comparison by the lack of an adequate description of N. challengeri

In 1951, Mr. H. W. Forrest, fishing in 220 fathoms off Manawarakau, Hawke Bay, New Zealand, found the first males of N. challengeri, two being obtained from the stomach of a groper, Polyprion oxygeneios (Bloch & Schn.). These specimens come to the Zoology Department through Dr. A. G. Clark, of Napier.

On January 27, 1954, the “Maimai,” trawling in 80–100 fathoms off Tora, between Castlepoint and Cape Palliser, East Coast of the North Island, New

Zealand, collected a male N. challengeri which was preserved by Mr. J. Thompson and came into my hands through Mr. J. H. Sorensen, of the Marine Department. This specimen, which is described below, was in good condition and still retained most of its original colour.

A large egg-bearing female N. challengeri was brought up alive in an otter trawl from 300 fathoms off the Chatham Islands on February 3, 1954 This was at Station 41 of the Chatham Islands Expedition, January-February, 1954, and I have to thank Mr. G. A. Knox, of the Zoology Department, Canterbury University College, leader of the Expedition, for allowing me to describe this fine specimen. I was able to examine it when it came to the surface and to record fully its brilliant colour pattern before this was lost on preservation.

The following description of Nephrops challengeri is based on the “Maimai” male. An account of the colour pattern and variation is also given using all four specimens available.