Key to genera of Cleidogonidae, based on mature males This key is adapted and simplified from the one in Shear (1972). 1a. Dorsa of the rings rough, with knobs or ridges and prominent shoulders, at least on the anterior rings; USA from central West Virginia and western Virginia south through North Carolina and Tennessee to northern Alabama and west through Kentucky to southern Ohio, Indiana and Illinois, often in caves................................................. Pseudotremia. 1b. Dorsa of the rings smooth, usually lacking prominent shoulders................................................2. 2a. Male ninth legs consisting of a single article with an apical tuft of ensiform setae; Tamaulipas, México ........... Cabraca 2b. Male ninth legs with at least 2 or 3 articles.................................................................3. 3a. Coxae of the male ninth legs elaborately lobed, telopodites usually reduced to 2 or 3 articles, ninth sternum with an anteriorly projecting knob; USA from Indiana south to Louisiana ................................................ Tiganogona 3b. Coxae of the male ninth legs with only a basal knob or distal apophysis, ninth sternum without an anteriorly projecting knob...4. 4a. Male ninth legs with elongate coxae and 4 to 6 telopodite articles, the prefemora enlarged, often triangular; eastern USA from Connecticut to Florida and west to Texas and Illinois, northeastern México (often in caves) south to Panama .... Cleidogona. 4b. Male ninth legs with 4 or fewer telopodite articles, prefemora not enlarged or triangular.............................5. 5a. Gonopods with a pair of sternal projections anterior to the angiocoxites; Panama ............................. Dybasia. 5b. Gonopods without sternal processes......................................................................6. 6a. Posterior branch of the gonopod angiocoxite massive, undivided; length greater than 20 mm; southeastern México, Guatemala ......................................................................................... Solaenogona. 6b. Posterior branch of the gonopod angiocoxite not massive, divided or undivided; length 9-16 mm; northeastern México and southern Texas, USA .................................................................... Lineagona, n. gen.

Published as part of Shear, William A., 2024, Lineagona, a new millipede genus (Diplopoda, Chordeumatida, Cleidogonidae) from Texas, USA, and Nuevo León, México, pp. 283-290 in Zootaxa 5397 (2) on page 285, DOI: 10.11646/zootaxa.5397.2.9, http://zenodo.org/record/10468747