Bovallius, 1887
Small animals. Five anterior pereonites fused in both sexes (Themistella fusca 1). Pereon fairly broad. Coxae fused with pereonites. Head fairly broad, without lateral lobes; head and pereon combined slightly shorter than pleon. ANT I 2-articulate, ANT II rudimentary in females, gland cone small. MD with serrate incisor; with palp in males, without in females. MXP almost completely lacking inner lobe (Themistella fusca 2). P moderately robust. P I and II chelate. P V longer than other. Dactyls of P VI and VII with flexure slightly distal to mid-length. Telson very short.
Monotypic.
Themistella fusca (Dana, 1852)