The occurrence of Kalicephalus sp. of hookworms in a Russell's viper snake maintained in Chennai snake park trust, Chennai is reported. These worms were found in the stomach and intestine. They were cylindrical, thread like and had an elongate body. Anterior end was obliquely truncated with bivalvular buccal capsule. Short, thick and muscularised oesophagus ending in a rounded bulb was observed. In males, a well developed trilobed bursa was observed and the spicules were short and equal. Typical strongyle type eggs were found in the uterus of female worms as well as in the intestinal contents.

The occurrence of the plerocercoid larva, Sparganum of Sparganum spp. in two Russell's viper snakes maintained in Chennai snake park trust, Chennai is reported for the first time from Southern India. The cestode larvae were found in the sub cutis and were flat, solid, wrinkled, ribbon like creamy white in colour with peudosegmentation with anterior end possessing bothria. The cuticles, subcuticular cells and parenchymatous tissue stained by acetic alum carmine further confirmed the cestode larvae.

The occurrence of the pentastomid Porocephalus crotali in an Indian rat snake (Ptyas mucosus) at Chennai, India is reported. The worms were found in the lungs and they were identified as females. The worms were cylindrical and annulated with a centrally located mouth surrounded by four hooks. The worms were rounded in cross section with tapering ends. Eggs were composed of two shell membranes. This is one of the new reports from rat snakes in Southern India.

Cell mediated immune response to immunoaffinity chromatography purified midgut antigen of Rhipicephalus haemaphysaloides ticks in rabbits was studied by using lymphocyte transformation test. This test was carried out by using 5-bromo-2 0 -deoxy-uridine kit method. The blastogenic response of peripheral blood lymphocytes of normal rabbit to different concentrations of antigen and mitogen (Con A) showed that 2 lg of antigen and 2 lg of mitogen gave maximum stimulation index. The antigen specific responsiveness of immunized rabbits with affinity purified 35 kDa midgut antigen was highly significant (P B 0.01) compared to mitogen. The maximum lymphocyte stimulation index (LSI) of 2.47 was observed on 49 day post immunization in immunized group. The lymphocytes separated from control animal cultured in RPMI1640 medium with 2 lg of antigen and 2 lg of mitogen (Con A) were never stimulated and their LSI values were below 2.0.