A New Species of Chaetoceratostoma

Abstract

This fungus could conceivably fall in the Chaetomiaceae, Melanosporaceae or the Ophiostomataceae. The genera in these families have several characteristics in common, notably, the presence of appendages, short or extended necks, ostioles and asci which are evanescent. In the Chaetomiaceae the organism resembles more closely Lopho? trichus in the membranous perithecia and spore characteristics. It differs mainly from Lophotrichus in the presence of spiny, lateral setae on the perithecium, in the absence of terminal hairs, and in the long, irregular length of the neck filaments. Also, in longitudinal sections (Fig. 5), there appears to be quite consistently a short stem-like struc? ture at the base of the perithecium. In view of these differences the organism was not placed in Lophotrichus. The fungus would apparently not fall in the Melanosporaceae because the spores show little variation in shape and the asci originate in a tuft at the base of the perithecium (Fig. 5) rather than forming a wall layer. In the Ophiostomataceae the asci show an irregular distribution throughout the centrum. This resembles the condition found in the new organism, although the arrangement of the asci does not seem to be very irregular. Other similarities are in the long beaks, appendages, darkcolored perithecia and evanescent asci. One difference is found in the color of the ascospores, which are dark in the new fungus and hyaline in the Ophiostomataceae. This characteristic should not warrant excluding the organism from this family. Dr. Julian H. Miller, who has kindly examined a culture of the fungus, agreed that the nearest form would be Chaetoceratostoma hispidum Turconi and Maffei (Att. Ist. Pav. 2: 15: 144. 1918). However, it differs mainly from that species in the possession of membranous