[2] Adults are small compared to other members of this genus; head is wider than long; snout appears pointed; nostrils are closer to the tip of snout rather than the eye; the nostrils are farther apart as compared to the distance between the eyes; tympanum is distinct and large, forming nearly 75% of the eye diameter; no webbing between fingers; first finger longer than the second but smaller than the third; foot longer than the femur and shank length; toes moderately pointed; fourth toe longer than others; webbing between toes are full, reaching the tips of all toes and sharply incised between toes; inner-metatarsal tubercle is indistinct; supratympanic fold present, but does not reach the base of arms; dorsum interspersed with small, rounded ridges; flanks, thigh and venter are smooth; a pair of dermal projections seen from anterior edge of forelimbs until groin.

[1] Phylogenetic analysis indicates that E. aloysii is closely related to E. hexadactylus and another potentially un-described species.

[1] This species is named in honor of Aloysius Gonzaga, a prince in Italy who entered the Jesuit order and died in Rome, serving people during an epidemic plague.

[1] The institution where one of the authors completed most work in describing the species is named after St. Aloysius as well.

Gravid females have been collected from the months of May until late July and implied that they may spawn in early August.