CAVE ENVIRONMENT. 201 



BIOLOGICAL ENVIRONMENT OF STYGICOLA AND LUCIFUGA. 



ASSOCIATES. 



During March small frogs are found abundantly at the margins of the pools 

 in some of the caves. I do not know that these affect the lives of the blind fishes 

 in any way. Tadpoles were found in the Carboneria well. It is possible that 

 these may form some part of the food of the fishes during some seasons of the 

 year. They are but casual associates of the blind fishes in some of the caves. 



Fishes other than the blind ones were found in Ashton and some of the small 

 open caves about Modesta. They were all Girardinits uictallicus Poey, a species 

 very abundant all the way to Pinar del Rio. The female reaches a maximum 

 length of 79 mm., but is usually much smaller; the maximum length of the male 

 is 45 mm. The largest specimens taken in Ashton are 41 mm. and 38 mm. These 

 fishes are active swimmers, living near the banks, and while a few may be cap- 

 tured by the blind fishes, they are themselves too small to attack even the young 

 of the blind fish. 



FOOD OF STYGICOLA AND LUCIFUGA. 



The blind fishes are carnivorous, securing living prey. Their food consists 

 largely of 4 species of crustaceans, 3 of which are blind cave forms. Probably 

 every living animal of the proper size is used by the blind fishes for food. 



Cirolana cubensis Hay. 



This species was described by Hay in Proceedings of the National Museum, 

 vi, page 430, as follows: 



Body oval, a little more than twice as long as broad, widest a little behind the middle, rather 

 strongly convex, and perfectly smooth. Head a little broader than long, slightly produced in front. 

 Mesosome broader, with its greatest width at the fifth segment; coxal plates of the second, third, 

 fourth, fifth, and sixth segments successively more enlarged and more strongly produced backward 

 at an acute angle. The plate of the seventh segment is about the same size as the one preceding it. 

 Metasome narrower than mesosome, of five segments, each of which, except the last, has the lateral 

 angles strongly produced posteriorly ; telson as long as the metasome, its margins gently curved 

 and convergent for about two-thirds of its length, and then rather abruptly strongly convergent to 

 form a short, obtuse tip. The eyes are altogether wanting. First antenna with three basal seg- 

 ments and a short flagellum which, when extended backward, reaches slightly beyond the posterior 

 margin of the first thoracic segment. Second antenna with five basal segments, and a long, slender 

 flagellum which may extend slightly beyond the middle of the body and is composed of about 

 twenty-nine segments. The mandible, maxilla?, and maxillipeds do not present specific characters 

 of importance, being of the type usual in the genus. The appendages of the mesosome are of mod- 

 erate strength, and are armed with a few rather stout spines and stiff seta?. The branchial append- 

 ages of the metasome are membranaceous and small; the uropoda are well developed, the outer branch 

 lanceolate in outline, the inner much broader and very slightly longer, and with the tip somewhat 

 accuminate; both branches and the margins of the telson as well bear a rather dense fringe of hairs. 

 Color in alcohol, white, with no markings of any kind. Length, 5 mm. 



Of the species of Cirolana known to inhabit American waters, C. mayana, which occurs on the 

 coast of Yucatan and Colombia, is the nearest relative of the present species. Between the two, 

 however, there are several important structural differences. The physiological differences between 

 this species and all the others of the genus must be very great to admit of its living in the subterranean 

 streams of fresh water. It may be added that Cirolana ciibcnsis is very distinct from Cirolanides 

 texensis Benedict, which occurs in the waters which flow from the large artesian well at San Marcos, 

 Texas. 



