Spinoncaea ivlevi (Shmeleva, 1966), female, robust form (northwestern equatorial Pacific) A antennule (separated between segments 3 and 4) B antenna, distal elements on distal endopod segment numbered using capital letters, lateral elements indicated by Roman numerals C mandible, individual elements indicated by capital letters D maxillule E maxilla, arrow indicating spinules on syncoxa, F maxilliped, posterior, syncoxa missing G labrum, anterior H labrum, posterior. Scale bars in μm.