Megalomma Johansson 1925
Creators: name: Tovar-Hernández, María Ana
name: Carrera-Parra, Luis F.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Megalomma

description: Key to American species of Megalomma   
1 Radiolar eyes present only in dorsalmost radioles........................................................... 2  
- Radiolar eyes not only in dorsalmost radioles............................................................... 5  
 2(1) Dorsal collar margins fused to faecal groove (Fig. 1A); anterior peristomial ring not exposed (Fig. 17A, D)...................................................................................... M. modestum (de Quatrefages, 1866)   
- Dorsal collar margins not fused to faecal groove (Figs 1D, 22E); anterior peristomial ring exposed (Figs 1D, 3A, 12A, 22E).................................................................................................... 3  
 3(2) Ventral shield of collar divided transversally in two parts (Fig. 23D, G); with caruncle (Fig. 23H)...................................................................................................... M. pigmentum Reish, 1963   
- Ventral shield of collar entire (Fig. 5C); caruncle absent....................................................... 4  
 4(3) Anterior peristomial ring exposed dorsally (Figs 3A, 5A); ventral basal flanges absent; inferior thoracic chaetae type B (Fig. 5G).......................................................................... M. bioculatum (Ehlers, 1887)   
 - Anterior peristomial ring exposed dorsally and laterally (Figs 12A–C, 13A–B, D); ventral basal flanges present (Fig. 13D); inferior thoracic chaetae type C (Fig. 1G)............................................ M. gesae Knight-Jones, 1997   
5(1) Eyes distributed only in 2–7 pairs of radioles............................................................... 6  
- Eyes distributed in most radioles........................................................................ 8  
 6(5) Spiraled eyes (Figs 24G–I, 25F–H); dorsal collar margins rounded posteriorly, showing the anterior peristomial ring partially (Fig. 24B)................................................................... M. splendidum (Moore, 1905)   
- Spherical eyes (Figs 7G–H, 11E–F)...................................................................... 7  
 7(6) Dorsal lappets present (Fig. 11A); eyes in seven pairs of radioles (dorsalmost and lateral radioles) (Fig. 7G–H).................................................................................... M. fauchaldi Giangrande et al. 2007   
 - Dorsal lappets absent (Fig. 7C); eyes in two pairs of radioles (dorsalmost and fifth dorsal radioles); with a glandular ring on chaetiger 3 (Fig. 7C)........................................................ M. coloratum (Chamberlin, 1919)   
 8(5) Dorsal margins of collar not fused to faecal groove (Fig. 1D); anterior peristomial ring exposed dorsally; ocular spots in ventralmost radioles (Fig. 26G)............................................................. M. georgiense n. sp.   
- Dorsal margin of collar fused to faecal groove (Figs 1A, 16A); anterior peristomial ring not exposed.................... 9  
 9(8) With dorsal lappets (Fig. 21A); inferior thoracic chaetae type A (Fig. 1E).................................................................................................. M. perkinsi Tovar-Hernández and Salazar-Vallejo, 2006   
- Dorsal lappets absent (Fig. 16A); inferior thoracic chaetae types B (Fig. 1F) or C (Fig. 1G)......................... 10  
10(9) With caruncle; interramal eyespots present in thorax and abdomen; inferior thoracic chaetae type B................... 11  
- Caruncle absent; interramal eyespots absent; inferior thoracic chaetae type C..................................... 12  
 11(10) Dorsal collar margins rounded posteriorly, showing partially the anterior peristomial ring.................................................................................. M. carunculata Tovar-Hernández and Salazar-Vallejo, 2008   
 - Dorsal collar margins level, covering the anterior peristomial ring (Fig. 16A)................ M. lobiferum (Ehlers, 1887)   
 12(10) Thoracic tori contacting ventral shields (Fig. 19C); ventral sacs and dorsal pockets present (Fig. 19B)................................................................................................... M. pacifici (Grube, 1859)   
- Thoracic tori separated from ventral shields (Figs 4B, 14C)................................................... 13  
 13(12) Radioles and anterior thorax with scattered dark spots (Fig. 14C, E–F); ventral sacs absent....... M. heterops Perkins, 1984   
 - Radioles and anterior thorax without scattered dark spots; ventral sacs present (Fig. 4D).. M. circumspectum (Moore, 1923)
description: Published as part of Tovar-Hernández, María Ana & Carrera-Parra, Luis F., 2011, Megalomma Johansson, 1925 (Polychaeta: Sabellidae) from America and other world-wide localities, and phylogenetic relationships within the genus 2861, pp. 1-71 in Zootaxa 2861 (1) on pages 13-14, DOI: 10.11646/zootaxa.2861.1.1, http://zenodo.org/record/5286352