the ' Challenger' Eryonidea. 223 



Specimen no. 4. — This specimen is not mentioned by Bate. 

 Median line formula as in no. 3. Lateral edge formula : 



5+3+5. 



Posterior half of the edge smooth. i( Fur" as in no. 1. 



Specimen no. 5. — Figured by Bate in pi. xix. 0. The 

 frontal margin forms a retreating angle, at the top of which 

 the rostral spines are situated. The carapace, when seen in 

 profile, is strongly arched. Median line spine-formula: 

 1 1 1121 1 1 CI 1 1111. 



These spines are small. Lateral edge spine-formula : 

 10+5+23, well-developed spines. 



The smaller spines spread over the carapace are more sparsely 

 set than in nos. 1, 3, 4, and 6. The first pleosomite carries 

 dorsally a well-developed hook, and the branchial ridge, 

 which is smooth in the other specimens, carries a row of 

 spines. 



Specimen no. 6 resembles nos. 3 and 4. Median line and 

 lateial edge-formulas as in no. 4. 



The conclusion I arrived at when examining the above 

 specimens is that they ought to be conceived as representatives 

 of four instead of one species, and I accordingly propose the 

 following names : — 



1. WiUemoesia leptodactyla, Willemoes-Suhm, repre- 

 sented by the type-specimen no. 1. 

 2. secunda, sp. n., represented by specimen no. 2. 



3. challengerij sp. n., represented by specimens 



nos. 3, 4, and 6. 



4. pacifica, sp. n., represented by specimen no. 5. 



Stereomastis sukmi, Bate. 



Bate's figure (pi. xv. fig. 3) is not very good, the form of 

 the body being, in fact, not very different from S. nana, 

 S. scidpta, etc. 



All the nine specimens, of sizes from 31 to 45 mm., were 

 taken at Stat. 311, and every one of them displays the same 

 median ridge spine-formula : 



2 112 2 1 C 2 (2) (2) 2. 



Bate gives it somewhat differently, making the two inter- 

 mediary, small, double spines appear as single, both in the 



