330 



THAXTER. — 



MONOGRAPH OF THE LABOULBEXIACE.E. 



in the case of L. cristata which occurs in all the continents; although the members of the large genus 

 Paederus which it infests, are very varied and numerous. On the other hand certain forms seem to be 

 decidedly restricted. L. variabilis, for example, which occurs on a variety of carabid hosts and even on 

 one genus of tiger-beetles, seems certainly not to occur outside the American continents. L. Phihnthi, 

 also, which occurs on members of one of the largest and most widely distributed genera of the Staphylinidse, 

 is only found in North and South America. In the two instances last mentioned, enough exotic material 

 of the hosts has been examined to make it reasonably certain that the species are thus restricted, and 

 this is doubtless true of many other forms in connection with which the data are less complete. Among 

 still more restricted forms the species on Hawaiian Carabidae may be mentioned, although they are in 

 general not confined to special genera; while numberless forms have as yet been seen only on members 

 of the same host species, or genus, and from single localities. 



In attempting to arrange the species serially, and at the same time bring together groups of evidently 

 related forms, a confusion has resulted in the following enumeration, through the unavoidable juxtaposi- 

 tion of unrelated species, and it would have been in some respects less misleading to have adopted an 

 alphabetical arrangement. The different groups of species, where groups can be distinguished, center 

 about the so-called normal, or flagellata-type. For example the whole series on American Galeritw, 

 already referred to, which comprises about twenty-five species, has apparently come from some type 

 similar to that of L. Mexicana, which is found widely distributed on the same hosts. The same may be 

 true of the group comprising L. Pachytelis, L. Pheropsophi, L. Texana with its varieties, and other related 

 forms; some or all of which may have come from L. Darwinii, or a similar type. The series of L. pro- 

 liferous and its varieties, comes also directly from a normal type through the proliferation of cell V; and 

 further abnormal divisions in this region result in the type of L. variabilis, which passes directly to the 

 types already referred to as seen in the aquatic parasites of Gyrinida 1 , which themselves vary to forms pos- 

 sessing quite normal receptacles. 



In my Monograph I called attention to certain abnormalities which were of interest as showing that 

 the sexual characters did not appear to be inherent in any special cells of the receptacle, although the 

 primary branches of the subbasal cell are normally antheridial and procarpic respectively. In this way 

 perithecia may be wholly or in part replaced by antheridial branches, and, especially in African forms of 

 L. proliferans, instances occur in which perithecia may arise secondarily from the subbasal cell, or even 

 other cells of the receptacle. 



Laboulbenia fasciculata Peyritsch. 

 L. brachiata Thaxter, Proc. Am. Acad. Arts and Sci., Vol. XXIV, p. 11. 



The figures of this species given by Peyritsch give so incorrect an idea of its characters, that I felt no 

 hesitation in separating the American form. An examination of European material on the same hosts 

 on which it was observed by Peyritsch clearly indicates, however, that the two are identical. Materia] 

 has been examined, from the Florence Collection on Platynus dorsalis Miill., on Pairobus excavatus Payk. 

 and on Chlaenius vestitus Payk., all of which were Italian ; in the British Museum on Pairobus rufipes 

 Fabr., from Britain, No. G38; on Brachinus sp., China (?) No. 535; the last two differing somewhat in 

 color but structurally identical with the North American and European types. Closely allied to L. 

 proliferans and resembling especially the varieties dinar icata and interposita, it is always separable from 

 the fact that the insertion-cell is undifferentiated and is not directly related to the basal cell of the inner 

 appendage. Each basal cell of the appendages, moreover, as well as the secondary appendiculate cells 

 which result from the proliferation of cell V, bear in the present species more than a single branch or 

 appendage; while the basal cells of the latter are relatively large and somewhat inflated, and all the 

 lower septa are black and somewhat oblique. The species bears also a certain resemblance to L. varia- 

 bilis to which it may be related. 



