Monsters in 4G but not Cross

Any of the Ashu (Alternate Breed) monsters
Sabita (Rusted) Kusharu Daora
Gurabimosu
Konton ni Umeku (Wailing in Chaos) Goa Magara
Gogumajiosu
Dala Amadura
Daren Mouran
Diaburosu
Dosu Jagii
Tigarekkusu Kishoushu (Rare breed, the red one that leaked Cheeto dust everywhere)
Neruskyura
Basarumosu
Babakonga
Takerihazeru (Severely Bursting) Burakidiosu 
Miraboreass (all three)
Monoburosu

Returning Monsters in Cross but not in 4G

Aoashira
Agunakotoru
Amatsu Magatsuchi
Arubatorion
Voruganosu
Uragankin
Ganototosu
Shougun Gizami
Dosu Gianosu
Dosu Fango
Dodoburango
Doboruberuku
Narugakuruga
Hapurubokka
Ragiakurusu
Rangurotora
Roa Rudorosu

Monsters in both 4G and Cross

Akamutorumu
Aru Serutasu
Ibirujoo
Ikari Kurau (Anger-Devouring) Ibirujoo
Iyan Garuruga
Iyan Kukku
Ukamurubasu
Urukususu
Oonazuchi
Garara Ajara
Kirin
Kusharu Daora
Kecha Wacha
Generu Serutasu
Geryosu
Goa Magara
Zaboazagiru
Shagaru Magara
Jinouga
Seru Regiosu
Daimyou Zazami
Tigarekkusu
Teo Teskatoru
Tetsukabura
Dosu Iiosu
Dosu Gareosu
Dosu Genebosu
Dosu Ranbosu
Burakidiosu
Furufuru
Raajan
Gekkoushita (Enraged) Raajan
Rioreia
Rioreia Kishoushu (rare breed, the golden one)
Rioreusu
Rioreusu Kishoushu (rare breed, the silver one)

Monsters New to Cross

Dinobarudo
Gamuuto
Raizekusu
Tamamitsune
Dosu Makkao
Hororo Horuru
Osutogaroa
The "Two Name Bearing" Monsters (some I'm not sure if I got the Romanizations for the kanji right - some were in Dengeki, so reasonably likely to be official, and Sekigan is an actual word.)

Benikabuto (Crimson Helmet) Aoashira
Ooyukinushi (Grand Snow Master) Urukususu
Hokokudaki (Lance Smashing) Daimyou Zazami
Shidokuhime (Purple Poison Princess) Rioreia
Iwaugachi (Opening Holes in Stone) Tetsukabura
Shiro Hayate (White Gale) Narugakuruga
Takaramato ? (Treasure Pile) Uragankin
Sekigan (Sharp Eyed) Iyan Garuruga
Kokuenou (Black Flame King) Rioreusu
Kinraikou (Gold Lightning Prince) Jinouga
Arakagitzume ? (Wild Hook Claw) Tigarekkusu
Jinmetsuyaiba ? (Incinerating Blade) Dinobarudo