188 BLIND VERTEBRATES AND THEIR EYES. 



Of Lucifnga ' 74 males have an average length of 63.5 with a maximum of 104, 

 and 82 females have an average length of 58 mm., with a maximum of 95. Only 

 specimens over 50 mm. in length were considered. 



While the average number of rays differs considerably in the two species, the 

 number in each varies so much that the numbers in individual cases overlap, the 

 individuals of Lucifnga reaching as high as 88 dorsal rays, and the individuals of 

 Stygicola as low as 87. The same is true with the anal. 



DISTRIBUTION OF STYGICOLA AND LUCIFUGA. 



Slygicola is known to be distributed from Jovellanos and Alacranes on the east 

 to Canas. Lucifuga is confined to the region from Guira de Helena westward to 

 Canas. The entire region between Alacranes and Canas on the southern slope is 

 drained by underground rivers. In the Canas region, the two species live side by 

 side with apparently no choice, except that while the young of Lucifnga are abun- 

 dant in shallow water among the roots of trees I have not been able to see or secure 

 Stygicola shorter than 60 mm. except as larvae from the mother. Stygicolas are 

 perhaps more abundant in the deeper, darker caves, though they are also found 

 in the shallowest, while lucifugas are more abundant in shallower, more open caves, 

 they in turn being found in the deeper caverns. Blind fishes resembling Stygicola 

 or Lucifnga have been reported to me from well-like caves at Merida, Mexico. 

 None have been captured. Other blind fishes which may be related to them are 

 said to occur in Jamaica. 



NATURE OF THE HABITAT OF STYGICOLA AND LUCIFUGA. 



Within the area over which they are distributed the blind fishes of Cuba live, 

 as far as known, in well-like caves in coralline limestone. The character of the 

 region in which they live can best be understood from an examination of the Finca 

 Carboneria, just outside of the Bay of Matanzas. There is here a coral strand 

 about on a level with high water. 



At the point of contact between ocean and land there is an abrupt wall, 5 to 10 

 feet high, profusely covered with seaweed, the nearly tideless water coming to the 

 .top of the wall where there are shallow, panlike pools replenished by waves and 

 spray. Immediately on top of the wall follows a low, naked, jagged mass of rock 

 resembling a huge sponge with its numerous pits and points. This area is in- 

 habited by innumerable mollusks. This low area is separated by a cleft (plate u, 

 fig. A) forming a sharp line of demarcation from a second zone similar to the first, 

 but in which the pits and depressions in the rock have become filled with sand which 

 gives foothold to tufts of plants. Over this lizards scamper from rock to rock. 

 Following this there is an abruptly sloping beach, the outer half of which is rocky 

 and sandy, partly covered with cactus and other low-growing plants, the inner or 

 land halt" being covered with shrubs and trees. All of these zones occupy per- 

 haps 100 yards. They are followed by the level, practically treeless, meadow, 



I In- following :i> i mint was published of the first 53 specimens of Lucifuga secured: The females are dis- 

 tinctly larger than the males. In making the average for the size of the sexes, individuals less than a year old 

 ;e ililfi-u-ni os in the sexes, if present, could be but very slight, and because in such young 



the sex could not always be- determined with certainty. An examination of all specimens makes it probable that 

 .it the i-nd of a year after birth the young are about 50 mm. long. In obtaining the average size of the sexes only 

 ovei qo mm. were considered. The males above this size measure 59.7 mm. on an average, with 

 a maximum of 94 mm. ; the females measure 71.1 mm. on an average, with a maximum of 93 mm. Of the speci- 

 mens over 50 in ; wore males and 22 females, or 100 females for every 104.5 males. Counting the fin 

 rays of I In- firs! i ; spa iim-us over 50 mm. long, we get males, D. 82.1, A. 67.4; females, D. 81.9, A. 68. The average 

 formula for those less than 50 mm. long is D. 83; A. 67.2, or for all together, D. 82.6; A. 07.5. 



